























Class -_Q P% 
Book_ T? b_ 

Gopight N°._ 


COPYRIGHT DEPOSIT. 









CUZZORT-TRASK HEALTH SERIES 


ESSENTIALS OF 
PHYSIOLOGY • HYGIENE 
AND SANITATION 


BY 

JOHN W. TRASK, M.D. 

SURGEON, UNITED STATES PUBLIC HEALTH SERVICE 
IN COLLABORATION WITH 

BELVA CUZZORT, A.M. 



D. C. HEATH AND COMPANY, PUBLISHERS 

BOSTON NEW YORK CHICAGO LONDON 



I 


CUZZORT-TRASK 
HEALTH SERIES 


Health Lessons 

For pupils under eight 

Primer of Personal Hygiene 

For pupils from eight to ten 

Health and Health Practices 

For pupils over ten 

Essentials of Physiology. Hygiene 
and Sanitation 
For pupils over eleven 


COPYRIGHT, 1923, BY 
D. C. HEATH & CO. 

2 G 3 


« 

» « 
? r C 


PRINTED IN U. S. A. 


AUG 11 1923 

©C1A752416 

At \ 




PREFACE 


If we would have a healthy, physically efficient race, the indivi¬ 
duals must live lives conducive to health and physical well being. 
They must have a desire to be healthy and realize that their well¬ 
being depends largely upon their habits of life and that their physi¬ 
cal fitness is a matter largely within their own control. 

The time to teach proper habits of living, “ health habits,” is in 
childhood. Healthy men and women are to be secured best, and 
perhaps only, by having the child develop “ health habits” which 
become second nature. But such habits, if they are to be rationally 
followed, must be based upon an underlying knowledge of the human 
body and of its needs and of the agencies which impair health and 
produce disease. 

It would seem reasonable to assume that there is nothing that 
can be taught to the boy and girl more important than how to keep 
well and strong, how to avoid disease, and how to prolong their 
lives. Such knowledge can not but make them happier, more effi¬ 
cient adults, and better citizens. An effort has been made in the 
text to discuss these things in such a way that the average boy 
and girl in the seventh and eighth grades will readily, and without 
particular concentration, understand; and understanding, will be 
filled with a desire to make and keep their bodies physically sound 
and fit. 

An attempt has been made to present the essential facts of hygiene 
and sanitation in a manner so simple as to be easily within the grasp 
and interests of the growing boy and girl. Amplifying and fixing 
in the mind the matters treated should be accomplished by class 
work. The first eight chapters deal with such anatomy and phys¬ 
iology of the body as it is believed the boy and girl should know. 
The teacher should illustrate these chapters by class work, for which 
the text provides a guide. 


IV 


PREFACE 


The purpose of the author has been to keep the book as small 
as possible and at the same time tell what the pupil should know 
and what his mind can grasp. Many details which constitute use¬ 
ful knowledge and which are often included in similar books, but 
which are seldom grasped by the pupil so as to become a part of 
his store of knowledge, and which act rather to bury and conceal 
the more important facts, have been omitted. That only has been 
included which it is believed the average pupil between eleven and 
fourteen years of age can mentally assimilate so readily that it will 
become part of his permanent store of information. 


John W. Trask. 


CONTENTS 


PART I — PHYSIOLOGY, OR WHAT THE DIFFERENT 
PARTS OF THE BODY DO FOR US 

CHAPTER PAGE 

I. Our Bodies and What They Are. 3 

II. The Bones and Their Purpose. 7 

III. The Muscles and What They Do for Us . . 17 

IV. The Brain and Nerves, and How They Control 

the Body. 25 

V. The Heart, Arteries, and Veins. 32 

VI. The Alimentary Tract, and What Becomes of 

the Food We Eat. 34 

VII. The Blood and How it Carries Food to our 

Muscles, Bones, and other Tissues ... 39 

VIII. The Lungs and Why We Breathe. 42 

PART II —PERSONAL HYGIENE, OR HOW TO KEEP 

WELL AND LIVE LONG 

IX. Food — Why We Eat and What to Eat. . . 49 

X. Food — Why We Eat and What to Eat 

(Continued). 55 

XI. Why We Drink and What to Drink .... 62 

XII. The Kind of Air We Should Breathe ... 65 

XIII. How Work and Play Train the Body. ... 68 

XIV. The Need for Sleep. 71 

XV. The Need for Regular Daily Habits. ... 75 

XVI. The Skin And Its Care. 80 

XVII. The Teeth and Their Care. 87 

XVIII. The Eyes and Their Care. 94 

XIX. Why We Wear Clothes and the Kind We Need 99 


v 















CONTENTS 


vi 

CHAPTER PAGE 

XX. Microbes, Good and Bad.103 

XXI. What Disease Is and What it Means ... no 

XXII. Why Some Diseases Spread from One Person 


to Another.117 

XXIII. What We Can Do to Protect Ourselves from 

Diseases Caused by Microbes.121 

XXIV. Some Diseases are Spread by Insects ... 127 

XXV. Tuberculosis. 133 

XXVI. Smallpox and Vaccination.138 


PART III — HYGIENE OF THE HOME 

XXVII. The Home. 

XXVIII. Heating the Home. 

XXIX. The Home (Continued). 

XXX. The Home (Concluded). 


M3 

147 

i53 

158 


PART IV — COMMUNITY, HYGIENE, AND SANITATION; OR 

WHAT OUR CITY AND STATE GOVERNMENT CAN 
DO TO PROTECT OUR HEALTH 


XXXI. How We Get Good Milk. 165 

XXXII. How We Get Good Milk (Continued) .... 171 

XXXIII. Water — What It Is; the Need for Good 

Water and How to Get It.178 

XXXIV. Sewage — What It Is and How Disposed of . . 185 

XXXV. The City Health Department and What It 

Does. 190 

XXXVI. The City Health Department and What It 

Does (Continued) .197 

XXXVII. The City Health Department and What It 

Does (Concluded) .201 

XXXVIII. The State Health Department and What It 

Does.205 

XXXIX. The United States Public Health Service . 209 

XL. Why Births and Deaths are Recorded ... 213 

















CONTENTS vii 

PAGE 

APPENDIX 

Directions for Keeping Clean.215 

The Bath; To Keep Scalp and Hair Healthy; To Care for 
the Nails; How to Care for the Hands and Face. 

Pasteurizing Milk at Home.216 

Pasteurizing Milk for the Baby; Caution in Pasteurizing. 

The Iceless Refrigerator.217 

Digestion of Foods.219 

First Aid Information and Practice.220 

Bandages.220 

Wounds.223 

Stopping Bleeding from an Artery; Stopping Bleeding 
from a Vein; Bleeding of Small Blood Vessels — the 
Capillaries; Burns. 

Drowning.226 

Artificial Respiration: (1) Air going into the Lungs; (2) 

Air going out of the Lungs. 

A First Aid Kit.227 

Index.229 













Apollo Belvedere 












PART I 


Physiology, 
Parts of 


or What the Different 
the Body Do for Us 



The Discus Thrower 

Shows a well developed body-machine 





ESSENTIALS OF PHYSIOLOGY, 
HYGIENE, AND SANITATION 

CHAPTER I 

Our Bodies and What They Are 

Our bodies are the houses in which we live. They are 
most wonderfully constructed. Our bodies as we see them 
consist of a head, a trunk, two arms, and two legs. By 
using our legs we can walk and run, by using our arms we 
can do many things. The trunk contains many important 
organs: a heart which pumps blood through our bodies, 
lungs by which we breathe, and a stomach and intestine 
which digest our food. 

Our heads contain our brains, eyes, and ears. With our 
brains we think, reason, remember, and store up knowl¬ 
edge. With our eyes we see the world about us. With 
our ears we hear the many noises and sounds, the song of 
birds and the rumble of thunder — we hear each other 
talk. 

Much of our success and happiness in life depends upon 
whether our bodies do their work well. If our brains can¬ 
not think and reason clearly, then we do not get along, we 
have trouble in school, and are likely to get into many 
difficulties. If our eyes do not see well, we miss many 
things. If our ears do not hear, we live in a noiseless 
world and do not have the pleasure of hearing people 
talk. If our hearts or lungs or stomachs are weakened, 

3 


4 


PHYSIOLOGY, HYGIENE, AND SANITATION 


we become invalids and are deprived of many of the joys 
of life. If we lose a leg or an arm, we are crippled. 

When our homes burn down, as they sometimes do, or 
are destroyed by the wind, as happens in some places, we 
can build new ones. But with our bodies it is different. 
Each of us can have but one body, which must last us 
during all our lifetime. If it becomes crippled or diseased, 
then we must get along during the rest of our lives with 
a body which cannot do many things. 

As our bodies are so important to us and have so great 
an influence on our lives, we will naturally want to make 
them just as good and strong as we can and will do every¬ 
thing to keep them in the best possible condition. Fortu¬ 
nately most of us can have good bodies if we want them 
and can keep them sound and useful if we really try. 

The various parts of our bodies become strong and 
skillful by proper use. They become weak and smaller 
if not used. If we use our brains to think and reason 
and study, then our brains become better and better able 
to think and to reason and to study. Every time we 
reason out a difficult example in arithmetic, we exercise 
our brains and make them better able to reason. The 
trained eye sees more than the untrained eye. The woods¬ 
man sees many things in the forest that others do not. 
The trained ear will hear and understand sounds that the 
untrained ear misses. How many many things the hands 
and arms can be taught to do! How much more skillful 
some are than others! And even our legs and feet can be 
trained. The untrained legs and feet are clumsy and 
stumble. We think of the deer as graceful in running, and 
of the mountain goat as sure-footed, but by proper use 
and training we too can be graceful and sure-footed. 


OUR BODIES AND WHAT THEY ARE 


5 


Training the various parts of our bodies to do their 
work well is a thing we should all aim to do, and this is 
what we do when we play and when we work. When we 
walk, run, or play games we are training our bodies. 
Baseball and tennis train the arms, legs, and bodies, so 
do tag, skating, and swimming, and the various outdoor 
games boys and girls play. We can train our bodies even 
while we walk to school. We can teach the muscles of 
the back and neck to hold the body straight and the head 
erect, and the lungs to breathe deeply. The best time to 
train our bodies is when we are young. It is much easier 
then than when we are older. 

But even after we have trained our bodies we must 
make them do things because they will not keep fit and 
in good condition unless we do. Our legs and arms and 
bodies and brains must be used or they get out of order. 
Using our bodies is sometimes spoken of as getting exer¬ 
cise. Sometimes we call it play, sometimes work. The 
man who works outdoors all day will exercise his brain 
in the evening by study. Or the man who works in an 
office will walk or play golf or tennis or baseball to exercise 
his body and legs and arms. 

To keep our bodies strong and fit we also must not let 
them get sick and diseased. Some diseases are due to 
eating improper food, some to improper habits. These 
we avoid by proper eating and living. Some diseases are 
due to what we call microbes or germs, and are got from 
others who are sick. We shall learn more about these 
later. 

We shall first learn how the body is built up of bones 
and muscles and tissues and how it contains organs which 
work for us and what the organs do. 


6 


PHYSIOLOGY, HYGIENE, AND SANITATION 


Questions 

1. What are our bodies? 

2. What do our bodies consist of? 

3. Do we need good sound bodies? Why? 

4. What happens if our eyes do not do their work well? 

5. What happens if our ears do not do their work well? 

6. What happens if our brains do not do their work well? 

7. What happens if our heart or lungs or stomach becomes 

injured? 

8. What happens if one loses a leg or an arm? 

9. If our bodies become damaged can we get new ones? Why 
not? 

10. Can we have good bodies if we want them? What do we 
need to do to have good bodies? 

11. How can we make our bodies strong and better able to do 
things? 

12. How do we make our brains able to think and reason better? 

13. Can we make our eyes better able to do their work? Can we 
train our ears? Our arms? Our legs? 

14. Why do we want trained bodies that are able to do things 
well? 

15. How does playing games train the body? 

16. How can we train our bodies while we are walking? 

17. When can the body be best trained to do things, when we 
are young or when we are older? Why do you think this is so? 

18. What happens if we do not use our bodies? What would 
happen if we did not use our arms for a long time? 

19. What do people mean by “ getting exercise ”? 

20. What may sickness and disease do to our bodies? 


CHAPTER II 


The Bones and Their Purpose 

Each of us has in his body over 200 bones. These are 
so joined together that they support the body, and make 
it possible for us to stand straight, and to walk about. 
The bones are fastened to each other in such a way that 
they form a framework to which softer parts of the body, 
such as the muscles, are attached. This bony framework 
is called the skeleton. It is the skeleton which makes it 
possible for us to stand upright. If we had no bones, our 
bodies would be much like large jellyfish or oysters. 

Some bones are long and slender, some are small like 
marbles, some are thin and flat. Their shape depends 
upon where they are in the body and what they have to 
do. Long bones are found in the arms and legs. Short 
round bones are found in the wrist and in the foot. Flat 
bones are found in the head, where they form a box to 
protect the brain. There are also bones which are very 
irregular in shape. Some of these are found in the face 
and other parts of the head. 

Bones are hard on the outside and usually softer inside. 
The long bones are hollow like a pipe. The hollow part 
is filled with soft material called marrow. The inside of 
some bones is like a honeycomb. The little spaces have 
walls of bone and are filled also with marrow. 

Bones are hard because they contain lime, just as the 
oyster shell which is made of lime is hard. But running 

7 


8 


PHYSIOLOGY, HYGIENE, AND SANITATION 





The Skeleton 

Showing the bones of the body, front and back. 

























THE BONES AND THEIR PURPOSE 


9 

all through the hard part of bones are small canals which 
contain little blood vessels and nerves. 

The Skull. — The bones of the head are called the skull. 
The skull is made up of 22 bones. Eight of these bones 
are so fastened together that they form a box. Inside of 
this box is the brain. 

The bony box protects 
the brain from harm. 

Fourteen of the bones 
of the head are in the 
face and give it its 
shape. All of the bones 
in the head except one 
are fastened together so 
that they do not move. 

This one bone is the 
lower jaw. It is fastened 
to the skull in such a 
way that it moves as 
though it were held by a hinge. By moving this bone 
up and down on its hinge we can chew our food and open 
and close our mouths. The skull rests upon and is sup¬ 
ported by the backbone or spinal column. 

The Spinal Column. — The spinal column is sometimes 
called the backbone, because it extends down the middle 
of the back. It is made up of 33 irregularly shaped bones 
called vertebrae. They are so joined together that each 
vertebra will move a little on the one above it and the 
one below it. The 33 bones taken together make the 
spinal column, which is about two feet long in an adult. 
While each vertebra will bend just a little on the one next 
to it, the whole spinal column will bend a good deal, as it 



Showing the bones of the head. 








IO PHYSIOLOGY, HYGIENE, AND SANITATION 


does when we stoop over and pick up something from the 
ground, or when we bend our bodies sidewise or backwards. 

The upper seven vertebrae are in the 
neck. The next twelve have ribs attached 
to them. The five below these are in the 
small part of the back at the waist. In 
the adult the next five vertebrae grow to¬ 
gether to form one bone called the sacrum, 
and the last four grow together and form 
one bone called the coccyx. 

The spinal column forms a strong pillar 
which supports the head. The vertebrae 
are so shaped that there is formed at the 
back of the spinal column a bony tube in 
which is the spinal cord. This cord is an 
extension of the brain. From it large 
nerves extend out through openings be¬ 
tween the vertebrae. 

The Thorax or Chest. — The thorax or 
chest is a bony cage inside of which are 
the heart and lungs. The bony cage pro¬ 
tects these important organs from harm. 
It is made up of the breast bone or sternum 
in front, the spinal column at the back and 
twelve ribs at each side. All the ribs are 
fastened to the spinal column at the back. 

The upper seven are fastened to the sternum 
The Back Bone or p reas t bone in front. 

umn, showing how The ribs llave s P ace s between them, but 
it is made up of these spaces are filled in by muscles which 

veZL° ne n:“ extend fr0m 0ne rib t0 the next The 

how it curves. ribs are so joined to the vertebrae behind 


THE BONES AND THEIR PURPOSE 


ii 


and the breast bone in front that they will move up and 
out when we breathe. This movement is shown when one 
takes a long breath and expands his chest. 

T he bony cage which makes the thorax opens at the top 
into the neck. At the bottom it is closed by a broad, 
flat muscle called the diaphragm . The diaphragm is used 
in breathing. 

The Arm. — The bones of the arm consist of the humerus , 
which is the long bone extending from the shoulder to the 
elbow, and of the radius and ulna , two bones which extend 
from the elbow to the wrist. The part of the arm between 
the elbow and the wrist is usually called the forearm. 

In the wrist are eight small bones so joined that they 
allow considerable movement, as will be seen by bending 
the wrist. Yet the eight bones are so fastened together 
that the wrist is very strong. The wrist bones are called 
the carpal bones. 

Below the wrist bones and joined to them are five 
slender bones in the palm of the hand. They can be felt 
through the back of the hand. There is one for each 
finger and one for the thumb. They are called the meta¬ 
carpal bones. 

Fastened to the metacarpal bones are the bones of the 
thumb and fingers. The thumb has two bones and each 
of the fingers three. These bones are called the phalanges. 
They are so fastened together that we can move each on 
the one next to it just as if it was fastened by a hinge. 
This is shown when we double up our fists. We can place 
the tips of our thumbs against the tips of each of the four 
fingers. We can also grasp hold of things and hang on to 
them with our hands. Very few animals can do this, 
The monkey can. 


12 PHYSIOLOGY, HYGIENE, AND SANITATION 


The arm is attached to the body at the shoulder by 
what is called the shoulder girdle. This is made up on 
each side of the collar bone or clavicle in front and of the 
shoulder blade or scapula behind. The clavicle is a slender 
bone joined at its inner end to the top of the breast bone 
or sternum. At its outer end it is joined to the shoulder 
blade. It keeps the shoulder out and prevents its falling 
forward. The shoulder blade or scapula is a flat bone and 
can be felt on each side, at the upper part of the back 
behind the shoulders. It can be felt to move when one 
moves his shoulder. The arm is joined to the shoulder 
blade in such a way that the arm can be moved in all 
directions, as when one throws a ball. 

The shoulder girdle, the arm, and the hand, all taken 
together, are called the upper extremity. The principal 
purpose of the upper extremity is to grasp and hold on to 
things. No animal has hands so well adapted to do this 
as our hands are. 

The Pelvis. — The lower end of the spinal column or 
backbone fits in between and is supported by two large 
irregularly shaped flat bones. They are called the ossa 
innominata or pelvic bones or sometimes the hip bones. 
There is one on each side. They are joined behind to the 
sacrum. They curve out and come together in front where 
they are joined together. The cavity between these bones 
is called the pelvis. These are the bones that we feel at 
our hips. They are also the bones upon which we rest 
when we sit. 

The Leg. — The part of the leg above the knee is known 
as the thigh. It has one long strong bone, the femur. 
The femur is the longest, largest, and strongest bone of the 
body. Except at the ends it is round like a broom handle. 


THE BONES AND THEIR PURPOSE 


T 3 


It is hollow in the center, however, so that it is probably 
better to say it is cylindrical like a gas or water pipe. 
The upper end is joined to the pelvic or hip bone on that 
side in such a way that it can be moved in all directions, 
in, out, forward, and back. 

In front of the knee is the knee cap or patella. It is a 
flat bone and can be moved with the fingers. It protects 
the knee in front. We rest upon it when we get on our 
knees. 

Between the knee and the ankle are two bones, the tibia 
and fibula. The tibia is sometimes called the shin bone. 
Next to the femur it is the longest and largest bone in the 
body. At the upper end it is joined to the femur, and at 
the lower end to the bones of the foot. The fibula is a 
slender bone. It is located on the outer side of the tibia 
and like it extends from the knee to the ankle. 

The Foot. — The heel and back part of the foot are 
made up of seven small bones called the tarsal bones. Of 
these the heel bone, which is called the os calcis, is the 
largest and strongest. The tarsal bones correspond to the 
carpal bones of the wrist. In front of the tarsal bones 
are five slender bones called the metatarsal bones. These 
correspond to the metacarpal bones of the hand. There 
is one metatarsal bone for each toe. They can be felt 
through the top of the foot. Joined to each metatarsal 
bone are the bones of the corresponding toe. The bones 
of the toes are called the phalanges of the foot. There are 
two bones in the great toe, as there are in the thumb, 
and three in each of the other toes, as there are in the 
fingers. 

The purpose of the legs is to support the body when we 
stand and to enable us to move about, to walk, and to 


14 PHYSIOLOGY, HYGIENE, AND SANITATION 


run. While the bones of the hand and foot resemble each 
other in their number and arrangement, the hand is con¬ 
structed for grasping things and the foot to support the 
weight of the body. For this reason the foot is shaped in 
the form of an arch. This arch sometimes gives way and 
becomes flattened. The condition is known as flat foot. 
When one has flat foot it is difficult to do much standing 
or walking. It is important that we take care of our feet 
and wear shoes that are properly shaped and which while 
supporting the arch do not cramp and distort the toes. 

Questions 

1. How many bones are there in the body? 

2. What do the bones do for the body? 

3. To what are the soft parts of the body attached? 

4. What would our bodies be like if we had no bones? 

5. What can you say about the shapes of bones? 

6. Where in the body are there long bones? Where are there 
round bones? Where flat bones? 

7. What is the outside of bones like? What can you say of the 
inside of bones? 

8. What is the inside of bones filled with? Have you ever 
seen the marrow of a bone in a beefsteak? Have you ever broken 
the leg bone of a chicken? What was the inside like? 

9. What makes bones hard? Do you know some things lime is 
used for? Do you know where the lime used in making mortar 
comes from? Where do you think the lime in our bones comes from? 

10. What is the skull? 

11. How many bones are there in the skull? 

12. What can you say about the shape of the skull? 

13. What is inside of the skull? 

14. What supports the skull? 

15. What is the backbone or spinal column? How long is it? 
How many bones in it? 

16. Does the spinal column bend? When do we bend our spinal 


THE BONES AND THEIR PURPOSE 


15 

columns? What would happen if we could not bend our spinal 
columns? 

17. What is the thorax or chest? 

18. What bones form the thorax? To what are the ribs fastened 
at the back? 

19. What happens to your ribs when you take a deep breath? 

20. What organs are inside the thorax? 

21. Can you feel your heart beat through your ribs? 

22. What is the name of the long bone of the arm between the 
elbow and the shoulder? 

23. What bones are there in the arm between the elbow and the 
wrist? 

24. What can you say about the bones of the wrist? Can you 
tell why the wrist can be bent in so many directions? 

25. How many bones are there in the palm of the hand? Can 
you feel them through the back of the hand? Count them. 

26. How many bones are there in the thumb? How many in 
each of the fingers? 

27. Show in how many ways you can move the fingers and 
thumb? Could you do this if there were no bones in them? 

28. What can we do with our hands that few animals can do? 
What animal can grasp hold of things and hang on to them just as 
we do? 

29. Do you know where your collar bone is? Do you know its 
other name? 

30. Do you know where your shoulder blade is? What is its 
other name? 

31. Can you feel your shoulder blade move when you move your 
shoulder backward and forward? 

32. What are the hip bones? What other names have they? 
Can you feel your hip bones? 

33. What part of the leg is called the thigh? What is the name of 
the bone in the thigh? 

34. To what bone is the femur joined at its upper end? In how 
many directions can the femur be moved? 

35. What is the knee cap? Can you feel it with your fingers? 
What is its other name? Of what use is it? 

36. How many bones are there in the leg between the knee and 


16 PHYSIOLOGY, HYGIENE, AND SANITATION 


ankle? Do you know their names? What is the other name for the 
shin bone? 

37. What is the heel bone called? 

38. In what way do the bones of the foot resemble the bones of 
the wrist and hand? 

39. In what way do the bones of the toes resemble the bones of 
the fingers? 

40. Can you move the toes in as many directions as you can the 
fingers? Can you grasp things with your toes? 

41. What do you use your hands for? What do you use your feet 
for? Can each do its own work best? What is flat foot? 

42. Could you walk and run if there were no bones in your legs 
and feet? Why not? 

43. Does one ever break the bones of one’s leg? What happens 
when a bone is broken? 

44. Do people ever lose their legs? How? 

45. What happens when one has one of his legs cut off? 

46. Would you want to lose one of your legs? Why not? 


CHAPTER III 


The Muscles and What They Do for Us 

In the preceding chapter we talked about the bony 
framework of the body to which the softer parts are 
attached. Now more than half of the softer parts consists 
of what are called muscles. It is the muscles of our bodies 
that make it possible for us to walk, run, talk, and do 
many other things. It is the muscles that move the 
different parts of our bony skeletons. If we move our legs 
or our arms, it is the muscles that do it. If we talk, it is 
the muscles of the chest, throat, mouth, and lips that 
enable us to make the different sounds. It is its muscles 
that enable the bird to fly, the deer to run, and the snail 
to crawl. 

The lean part of meat is muscle. All of a beef steak 
that is not bone or fat is muscle. When we eat meat it 
is usually the muscle that we eat. Of course there may 
be some fat with it which is not muscle. It has been 
explained that the soft parts of the body are usually at¬ 
tached to the bones. You have noticed how the lean 
meat in a steak or a chop is fastened to the bone. 

Muscles are made up of many little fibers somewhat as 
a rope is made, except that the muscle fibers are shorter 
than those in a rope and are fastened together but not 
twisted. These muscle fibers have the power to contract, 
that is to make themselves shorter. When they make 
themselves shorter, they at the same time become thicker 

17 


18 PHYSIOLOGY, HYGIENE, AND SANITATION 




Muscles of the Body 

As they would appear if they were not covered by the skin. 


I 















THE MUSCLES AND WHAT THEY DO FOR US 19 


just as an angleworm does when it crawls. When the 
fibers in a muscle contract, the whole muscle becomes 
shorter, and if the muscle is attached to a bone, the bone 
moves. If the bone is a leg bone, the leg is moved. 

Muscles differ in shape. Some are long and slender like 
those in the arms and legs. Some are broad and flat like 
those forming the front walls of the abdomen. There is a 
muscle around the mouth shaped like a ring. When this 
muscle is contracted, the mouth is puckered and made 
smaller. Pucker your mouth and you will see how it 
works. 

One of the uses of muscles is to make it possible for us 
to move about. By contracting the various muscles of 
our legs, first one set of muscles and then another, we are 
able to lift our feet one at a time, and move the leg for¬ 
ward, first one leg and then the other. In this way we 
walk. If we want to raise our hand to our mouth we do 
it by contracting the muscles of the arm and forearm. 

Put your left hand on the muscle of your right arm 
between the shoulder and elbow. Now move the right 
hand up and down and you will feel the muscle under the 
left hand contract and bulge as the hand is raised and 
lengthen and flatten out as the right hand goes down. 
When the muscle bulges it contracts and pulls up the fore¬ 
arm and the hand. Shut your right hand up hard in a 
fist. Notice how the muscles in the thick part of your 
forearm harden and bulge. These are the muscles which 
close your hand and hold it shut. 

When we chew food, it is the muscles of our cheeks that 
work the lower jaw. Place your fingers over one side of 
your face a little in front of one ear and feel how the 
muscle hardens and bulges when you shut your mouth 


20 PHYSIOLOGY, HYGIENE, AND SANITATION 


tight. These are the muscles that work the jaw when 
you chew your food. 

The ends of many muscles are made up of tough, fibrous 
tissue called tendons. In many instances the muscles or 
their tendons pass over the bone joints, and being fastened 
to the bone above and below the joint, help to hold the 
joint together and to protect it. Thus there are a number 
of muscles which are fastened to the bone of the thigh 
above the knee by their upper ends and to the bones of 
the leg below the knee by their lower ends. These muscles 
help to hold the knee joint together. There are also 
muscles which help hold the elbow joint together, being 
fastened at one end above the elbow and at the other end 
below the elbow. 

The abdominal wall is composed mainly of broad flat 
muscles. These are arranged in layers. The fibers of 
some run up and down and of some crosswise. Still others 
have their fibers slanted diagonally. All together they 
form a wall which holds in and supports the important 
organs of the abdomen. When these muscles are in good 
condition and strong they hold the organs well in and the 
abdominal wall is flat or but slightly curved out. When 
the muscles get weak, the weight of the abdominal organs 
pushes the wall out and causes what is sometimes called 
a big stomach. 

The shape of the body is what it is mainly because of 
the muscles. If it were not for the muscles, our legs and 
arms would consist of little more than bones and blood 
vessels. It is the muscles that make them the size they are. 
It is the muscles of the body that give it the shape and 
curves it has. The skin and the layer of fat just beneath 
the skin help too, but the muscles are the most important. 


THE MUSCLES AND WHAT THEY DO FOR US 21 


The heart, of which we shall tell more later, is made up 
almost entirely of muscle. It is hollow, and when it con¬ 
tracts it pumps the blood through our bodies. Every time 
it beats, the muscle in its wall contracts, making the heart 
smaller, and forcing the blood out into the arteries. 

We can contract some of our muscles whenever we want 
to, as we do the muscles of our arms, legs, 
and face. These are called the voluntary 
muscles because we use them voluntarily. 

There are other muscles in the walls of the 
stomach and of the intestines, which con¬ 
tract and work whenever there is food in the 
stomach or intestine. Over these muscles 
we have no control. We cannot make them 
contract or stop their working. Because we 
have no control over them they are called 
the involuntary muscles. 

While all muscles look much alike, yet 
under the microscope we find that there is 
a difference. The fibers of the voluntary Voluntary or 
muscles have cross markings, and because Striped Muscle 
of this are spoken of as striped muscle. The 11 looks 
involuntary muscle fibers have no cross through a micro¬ 
markings and are called unstriped muscle. scope - ^. otlc< : 

. cross markings of 

When a muscle contracts it produces the muscle cells. 

heat. Much of the heat of our bodies is These are the 
. . . ,. . - r kind of muscle 

produced m this way, for some of our ce ii s found in the 

muscles are at work all the time. You all muscles of the 

know that if you are cold, walking fast or arms and legs ' 

running will warm you up. The body is made warm 

because of the heat produced by the muscles used in 

walking or running. This explains why when a person 













22 


PHYSIOLOGY, HYGIENE, AND SANITATION 


is cold and in danger of freezing he should keep walking 
to keep the body warm, and why he should not lie down. 

When a muscle is made to contract a great number of 
times, it gradually tires and does not contract so strongly 
as at first. In time it will stop contracting entirely. The 

muscle is then said to be 
fatigued. If it is allowed to rest 
for a time, the muscle will re¬ 
cover from its fatigue and will 
again work just as hard as it 
did at first. 

If we use our muscles prop¬ 
erly they grow larger and 
stronger and tire less and less 
easily. If we do not use them, 
they get small and weak and 
tire quickly. If you ever had 
your arm or leg in a splint for 
two or three weeks, you know 
how small and weak the muscles 
became. If we use one set of 
muscles a great deal, they be¬ 
come large and hard. In men who are shoveling dirt and 
coal all day long, the muscles of the arms, shoulders, and 
back become large and hard. It is much better for most of 
us to exercise all our muscles some so that no muscle will be 
weak. All the muscles of our arms and legs and bodies 
should be exercised enough by play and work to keep them 
fit. We do not want to have big bulging muscles unless 
we are going to have daily use for them, as in lifting heavy 
loads or in swinging a sledge. Muscles will not stay big 
Unless they are used. And big muscles are of no advantage 



Muscle Cells from 
the Heart 

As they appear when seen 
through a microscope. 















































































THE MUSCLES AND WHAT THEY DO FOR US 23 

unless they are needed for heavy work. For most of us it 
is better to be agile and skillful in doing things than to be 
able to lift heavy weights. It is better to be able to play 
baseball or tennis than to be able to run a long distance. 

Moderately developed muscles are more useful for most 
of us, and they also give the body a better and more 
pleasing shape. 

Remember that our muscles make up a large part of our 



Involuntary or Unstriped Muscle Cells 

As they appear when seen through a microscope. These are the kind of 
muscle cells found in the walls of the stomach and intestines. 


body weight, and besides making it possible for us to per¬ 
form many useful acts they have much to do with main¬ 
taining the symmetry and gracefulness of our bodies. 

Questions 

1. What are the muscles? 

2. Does much of one’s body consist of muscles? 

3. What do our muscles do for us? What things do your muscles 
make it possible for you to do? 

4. What part of beef steak is muscle? 

5. What can you say about what muscles are made of? 

6. What do we mean when we say that a muscle can contract? 

7. What happens when we contract one of the muscles fastened 
to a bone? What do you do when you feel the muscle of your arm 























24 PHYSIOLOGY, HYGIENE, AND SANITATION 


as boys often do? Can you feel it contract and bulge, that is get 
shorter and thicker? Grasp the right forearm with the fingers of 
your left hand. Now open and clench your right fist. Can you feel 
the muscles of the forearm harden and get thicker? 

8 . What can you say about the different shapes of muscles? 
Why do you think muscles have different shapes? 

9. What is the shape of the muscle around the mouth? What 
happens when it contracts and becomes smaller? 

10. To what are muscles usually fastened? What are tendons? 

11. How do muscles help to strengthen joints? 

12. What is the shape of the muscles in the abdominal wall? 
What do these muscles do for us? When the muscles get weak 
what happens? 

13. In what way do the muscles give the body its shape? What 
would one’s leg look like if it had no muscle? 

14. What is the heart made of? Do you know what the heart 
does? 

15. Are there muscles in the walls of the stomach? Can you 
make the muscles of the stomach contract whenever you want to 
as you can the muscles of the arm? 

16. What are the muscles called which you can contract when 
you want to? What are the muscles called over which you have 
no control? 

17. Why are voluntary muscles sometimes called striped muscles? 
Why are involuntary muscles called unstriped muscles? 

18. How do muscles produce heat? Why does running make you 
warm? 

19. What happens to a muscle when it is kept working a long 
time? Can you tell why you get tired when you run or play hard? 

20. How can we make our muscles stronger and so they will not 
tire so easily? 

21. What happens to a muscle that is not used much? 

22. Does one want big bulging muscles? Why not? 

23. What kinds of muscle are most useful? 

24. What makes the deer graceful in its movements? 

25. In what way do properly developed muscles make one’s 
body look better and make one more graceful? 


CHAPTER IV 


The Brain and Nerves and How They Control the Body 

Inside the head is the brain. It is perhaps the most 
important organ of the body. It is protected from injury 
by the bony walls of the skull. Like all the other organs 
it is made up of cells, but the cells of the brain are different 
in shape from the cells which make up the other organs. 
These cells are all so small that we cannot see them unless 
we use a microscope. Some of the cells have many branches 
like a tree. All have at least one branch or projection. 
Some of the cells have one very long projection which 
under a microscope looks like a thread or a fine wire. 

Connected with the brain is the spinal cord, which ex¬ 
tends down in the center of the backbone or spinal column. 
The spinal cord is made up of cells resembling those in the 
brain. The brain and spinal cord taken together are called 
the central nervous system. 

Extending out from the brain and spinal cord are what 
are called nerves. The nerves are made up of the long 
projections of the cells of the brain and spinal cord. These 
projections might be thought of as tails of the cells, but 
the cells are so small and these projections are so long 
that one would think of them more as being like fibers or 
wires. We will call them nerve fibers. Some of them are 
two or three feet long or even longer. They are as long 
as the nerves which they make up. There is one nerve 
which extends from the lower part of the spinal column 

25 


26 PHYSIOLOGY, HYGIENE, AND SANITATION 


down the leg to the toes. The nerve fibers in this nerve 
are as long as the nerve itself, for the cells to which these 
fibers are attached are in the spinal cord. 

The brain and spinal cord send out their nerve fibers 
in bundles called nerves to all parts of the body. It is 
through these nerves that we control the movements of 
the body. When you pick up a pencil from your desk, 



Nerve Cells from the Brain and Spinal Cord 

As they appear when seen through a microscope. Notice how they 

all have branches. 


you do it because the brain sends a message down through 
the nerve fibers which extend down the arm and to the 
hand. These nerve fibers end in the muscles — some in 
the muscles of the shoulder, some in the muscles of the 
arm and hand. When the message comes from the brain, 
it runs down certain of the nerve fibers, and when it 
reaches the muscles at the end of the fibers, it causes the 
muscles to contract. In this way you move your hand 
forward to where the pencil is, place your fingers on the 
pencil, and pick it up. 











THE BRAIN AND NERVES 


2 7 


The way the brain sends messages through the nerve 
libers to the muscles is much like sending a telegram over 
a telegraph wire. The wonderful part of it is that the 
brain can tell just which muscles to contract when you 
want to do a certain thing. When you play ball, the brain 
has to tell the right muscles just when to act. The brain 
has to cause the muscles to act differently when you 
throw a ball, or catch it, or bat, 
or run bases. Whatever you do, 
the brain has to tell just the right 
muscles. Learning to do a thing 
is really teaching the brain how 
to control the muscles and make 
the right ones act at the right 
time. When you learn to swim 
or skate, it is the brain and spinal 
cord that you are teaching. They 
are the ones that must learn how 
to do it. 

We have learned how the brain 
is connected with the muscles of 
the body by the nerve fibers and 
why we can move our arms and legs when we want to, but 
there are also other nerve fibers that run to many parts of 
the body, especially to the skin. These fibers carry mes¬ 
sages to the brain. The others you remember carried 
messages from the brain to the muscles. These fibers 
carry messages from the skin to the brain. 

When you burn yourself, it hurts, and you feel pain. 
This is because the heat injured the little nerve endings 
in the skin, and immediately the nerves carried the mes¬ 
sage to the brain, and you felt the pain. If you touch a 



Showing How the Nerves 
Extend to All Parts of 
the Head and Face 










28 PHYSIOLOGY, HYGIENE, AND SANITATION 

hot object with your finger, as soon as the brain feels the 
pain it sends a message to the muscles of your arm and 
causes them to pull your hand away so it will not keep 
on getting burned and possibly badly injured. So you see 

the pain really serves a use¬ 
ful purpose and protects us 
from serious injury. 

It is much the same if you 
run a pin into your hand 
or a nail into your foot. The 
little nerves that are injured 
carry the message to the brain 
and you feel the hurt. You 
then remove the pin or the 
nail. If it were not for these 
nerves, you would not know 
the pin or nail was there, and 
it would probably do you 
much more injury. 

If a thing that is hot 
touches your skin, you know 
it is hot. If the thing is cold, 
you know it is cold. If a 
heavy object is resting on 
your foot, you know it is 
heavy. Different nerve fibers tell your brain these things 
so that it will know just what to do. The nerve fibers 
that can tell when a thing is hot are different ones from 
those that tell when it is cold. And still other fibers tell 
when an object is neither hot nor cold but just heavy. 

So you see the skin is filled with the ends of these little 
nerve fibers, and they are all there to tell the brain when 























THE BRAIN AND NERVES 


2 9 


we are being injured and in this way keep us from getting 
badly hurt. 

There are other nerve libers which connect the brain 
with the heart, lungs, and stomach. The brain controls 
these organs by the messages it sends through the nerve 
libers, but it does it without our know¬ 
ing it. It is fortunate that it is so and 
that we do not have to be thinking all 
the time about our heart and lungs. 

The brain, without our knowing it, 
keeps them working just right all the 
time. When the body needs more 
blood it makes the heart beat faster. 

When it needs more air, 
it makes the lungs take 
deeper breaths and work 
harder. 

But most wonderful 
of all, it is with 


our 



brains we do our think- This Man by Practice has Taught 
ing. It is through the HIS T ° 

working of little cells in 

the brain, that you learn your lessons. It is by the work¬ 
ing of the brain cells that you do your problems in arith¬ 
metic. It is by the working of these cells that we remember 
to-day what we learned yesterday. It is the brain cells 
that tell us when we are happy and when we are sad. 

When we sleep, it is really our brain that sleeps. When 
we sleep we neither see nor hear, and the brain does not 
keep telling us about the things around us. However, the 
brain does not stop working entirely. It keeps the heart 
beating and the lungs breathing. But they do not need 






30 PHYSIOLOGY, HYGIENE, AND SANITATION 


to work so hard as when we are awake, because when we 
sleep the body is quiet and does not need so much blood 
and air. So when we sleep our body rests, and although 
the brain keeps the heart and lungs working a little, they 
all rest. 

When we feel tired, it means we need rest. When we 
feel sleepy, it means we need sleep. It means the brain 
and body have been working hard and want to rest. 
Our brains and bodies must have enough rest and sleep 
or they will not work well. You cannot play ball or skate 
or swim well when the body is tired, and you cannot 
study well when the brain is tired and has not had enough 
sleep. You learn your lessons much better when the 
brain is rested and has had all the sleep it needs. 

If we want to do good work at school, we must have 
plenty of sleep, for a brain that is not rested will not work 
as well as it should. 


Questions 

1. Where is the brain? 

2. Of what is the brain made? 

3. What can you say about the shape of the brain cells? 

4. Where is the spinal cord? In what way does it resemble the 
brain? 

5. What are the brain and spinal cord together called? 

6. What are the nerves? 

7. What are the nerves composed of? 

8. What are nerve fibers? How long are some of them? 

9. Of what use are the nerves? When you pick up a pencil, 
what has happened to the nerves going to the arm? What has the 
brain done? 

10. When you learn to do a thing, what part of your body is 
it that has been taught just how to do it? 

n. When you learn to swim, what part of you do you teach? 
Explain why. 


THE BRAIN AND NERVES 


31 


12. Touch your nose with your finger. Tick up a pencil. Tell 
how the brain and nerves make it possible for you to do these things. 

13. What happens when you touch something which is hot? 
How do you know it is hot? 

14. If you were to put your hand against a hot stove, and could 
not feel that it was hot, what would happen? Why is it fortunate 
that we feel pain when we touch hot things? 

15. If you run a pin into your finger how do you know what has 
happened? What do you do? 

16. How can you tell when a thing is cold? 

17. How do you know when something heavy is resting on your 
foot? 

18. Tell how your nerves protect you from injury. 

19. Tell how the brain and nerves keep the heart and lungs 
working. 

20. What part of your body do you use when you think? When 
you learn your lessons? When you do an example in arithmetic? 

21. What happens when we sleep? What does the body do when 
we sleep? 

22. Can a tired brain do good work? Why not? 

23. What does sleep do for our bodies? 


CHAPTER V 


The Heart, Arteries, and Veins 

When you cut your finger or toe, it bleeds, and blood 
runs out of the cut. Wherever you cut your body, you 

will find there is blood. 

If you hold your hand over 
the left side of your chest in 
front, you will feel your 
heart beat. The heart is really 
a hollow pump made of 
muscle, and when it beats it 
is pumping blood to all parts 
of the body. It pumps the 
blood through pipes called 
arteries. Near the heart these 
pipes or arteries are large. 
Then they divide and become 
smaller like the branches of a 
tree. Finally they become 
very small. In the end of 
the finger they are so small 
you cannot see them. These 

face. In running the race he has very small arteries have thin 

worked his heart very hard and walls, and some of the fluid 
may have done it some injury. r J . . . . . . 

of the blood passes through 
the walls to nourish the skin, muscle, and bone cells. 

The rest of the blood then starts back to the heart 
through small vessels called veins. A lot of little veins 
join together and form a larger vein. These veins later 



32 




The Heart and the Large Showing how the Arteries 
Arteries (red) into which it carry Blood to all parts oe the 
pumps the Blood, and the Head and Face. 

Large Vein (blue) which 

BRINGS THE BLOOD BACK TO IT. 



Showing how the Arteries Showing how the Arteries 

carry Blood to all parts of carry Blood to all parts of 
the Leg and Foot. the Arm and Hand. 




















































THE HEART, ARTERIES, AND VEINS 


33 


join and make still larger veins. Finally they all join 
one big vein and this carries the blood back to the heart. 

The heart does not send this blood right back again to 
the muscles and bones and other tissues, but first sends it 
to the lungs to get some air. Then this blood returns to 
the heart, and freshened by the air it got in the lungs is 
again pumped to all parts of the body. 

We spoke of the heart as a pump. It is really two 
pumps joined together. One of these pumps sends the 
blood to the lungs for air, and when the blood comes 
back to the heart the other pump sends it to all parts of 
the body to feed the body cells. All the organs and parts 
of the body are made up of little cells which have to be 
nourished, and it is the blood that carries to them the 
food and water they need. 

Questions 

1. What happens when you cut yourself? 

2. What is the heart made of? What does it do? 

3. What are arteries? What are they like? 

4. Where are the arteries large? Where are they small? 

5. What happens to the blood in the smallest arteries in the 
finger, in the skin and in the muscles? 

6. What happens to the blood after it passes through the small¬ 
est arteries in the finger? 

7. What are veins? 

8. How does blood find its way back to the heart? 

9. When the blood flows back to the heart through the veins, 
where does the heart send it next? Why? 

10. What happens to the blood when it is sent to the lungs? 

11. After the blood has passed through the lungs, where does it 
go? What does the heart then do with it? 

12. What does the blood carry to the muscles, skin and bones? 

13. How do all the body cells get water and food? 


CHAPTER VI 


The Alimentary Tract and What Becomes of the 

Food We Eat 

The alimentary tract is that part of the body through 
which the food passes. It begins at the mouth, then 
comes the throat, then the esophagus, the stomach, and 
the intestine. It is like a long tube, bigger in some parts 
than others. The stomach is the biggest part of the tube. 
It is where the food first stops when we swallow it. . 

The food we eat is what nourishes all the cells of the 
body. The body must have food or it will die. An auto¬ 
mobile gets its power by burning up gasoline. A locomo¬ 
tive gets its power by burning up coal. Gasoline is the 
food of the automobile and coal is the food of the loco¬ 
motive. Our bodies get their power to do things by 
burning up the food we eat. The heart has to have food 
or it will stop beating. The lungs have to have food or 
they will stop breathing. Our muscles use up food when¬ 
ever they work. 

Food is not only burned up to give the body power and 
strength to do things, but some of the food is used to 
build up the body. Some of it is actually changed into 
muscle and bone and skin. Our bodies grow because the 
food we eat is changed into our flesh and blood. 

Before food can be used by the body, it has to be ground 
up and changed into a liquid form. That is why the 
first thing we do when we eat is to chew our food up fine. 

34 


THE ALIMENTARY TRACT 


35 


The finer we chew it, the better. Our teeth are given us 
for this purpose. When we chew our food, we not only 
grind it up, but we also mix with it the saliva of the mouth. 

The saliva makes the food moist and slippery, so that 
it can be easily swallowed. It also starts the process of 
making the food into a liquid form. Making the food into 



The Stomach 

This is where the food goes when it is swallowed. It is partly 
digested here and then passes on into the intestine. 


a liquid form in which it can be used by the body as fuel 
and for building muscle and bone is called digestion. 

After the food is well chewed and moistened thoroughly 
with saliva, it is swallowed. It passes into the throat and 
from there into the esophagus. It passes down the esoph¬ 
agus and into the stomach, where it undergoes further 
digestion. The esophagus is a tube about nine or ten 
























36 PHYSIOLOGY, HYGIENE, AND SANITATION 

inches long and has walls made up mostly of muscles. 
These muscles force the food along the esophagus and into 
the stomach. 

The food remains for some time in the stomach, where 
it is mixed with a liquid called gastric juice. This gastric 
juice comes from little glands in the walls of the stomach. 
It is sour and contains acid. It helps dissolve and digest 
certain parts- of the food, especially lean meat. 

The stomach walls contain many flat muscles which 
keep contracting whenever there is food in the stomach. 
In this way the food is churned and well mixed with the 
gastric juice. The food stays in the stomach until it 
becomes a thick, soupy liquid. Then it passes but of the 
stomach into the intestine. 

In the intestine other digestive liquids are mixed with 
the food, and here digestion is completed and the food 
passes through the wall of the intestine and into the 
blood. The food is then carried by the blood to all parts 
of the body, where it is used to do work and to build up 
the muscles, bones, and other tissues. It takes several 
hours for a meal to become digested in this way. 

Some of the meat we eat contains tough gristle and 
sinew. This is what sometimes gets stuck between our 
teeth. Some of the vegetables we eat have tough, woody 
fibers in them. Parts of celery and asparagus have these 
tough fibers. The gristle of meat, the tough fibers of 
vegetables, and such things as the skins and seeds of 
apples, do not digest. They pass along with the food 
unchanged, and finally pass out of the alimentary tract. 

To repair and build up the tissues and organs, the body 
has to have many kinds of food. We cannot be strong and 
healthy if we eat only meat, or only rice, or only bread. 


THE ALIMENTARY TRACT 


37 


Our bodies need a little meat or eggs, some milk, some 
vegetables, some fruits, some bread, and much water. 
Water is as necessary as any food. Milk is a good food, 
especially for growing children, as it contains lime and 
other things the body needs. Fruits and such vegetables 
as lettuce and spinach are also very good foods, for they 
contain some of the things the body must have to build 
up the tissues. 

Some of our food we eat raw, some of it we cook. We 
cook some food to make it taste better. Some we cook to 
make it more easily digested. Some food we cook to make 
it soft and more easily chewed. However, we should not 
eat all soft food. We should have some food that is hard 
to chew, because the teeth need exercise. If we give the 
teeth plenty of work to do chewing the harder kinds of 
food, it will help keep them strong and in good condition. 
The teeth need work to keep them healthy just as the 
muscles do. 


Questions 

1. What is the alimentary tract? What is it like? Name some 
parts of it? 

2. What is the stomach? 

3. What does the food we eat do for our bodies? 

4. In what way is our food like the coal burned in a locomotive? 
How is it like the gasoline in an automobile? 

5. What does our food do for us besides give us strength to do 
things? 

6. How does food make us grow? 

7. What has to be done to food before it can be used by the 
body? 

8. What are our teeth for? 

9. Why do we chew our food up fine? 

10. What do we mean by digestion of food? 


38 


PHYSIOLOGY, HYGIENE, AND SANITATION 


11. When we take food into our mouths what do we do? 

12. When we have chewed our food up fine and swallowed it 
where does it go? 

13. How long is the esophagus? 

14. What happens to the food when it reaches the stomach? 

15. What is the gastric juice? Where does it come from? 

16. How long does the food stay in the stomach? 

17. Where does the food go when it leaves the stomach? What 
is the food like when it leaves the stomach? 

18. What happens to the food when it reaches the intestine? 

19. When food is completely digested, where does it go? How 
does it get into the blood? What does the blood then do with it? 

20. How long does it take food to become digested and ready to 
be taken up by the blood? 

21. Do we digest all the food we eat? Why not? 

22. What becomes of the parts of food we can not digest? 

23. Can you tell why we drink water? 

24. What different kinds of food do our bodies need? 

25. Why is milk an important food? Why are fruits and vege¬ 
tables important? 

26. What foods do we eat raw? 

27. What foods are cooked before being eaten? 

28. Why do we cook some foods? 

29. Why should we eat some hard foods? 


CHAPTER VII 


The Blood and How it Carries Food to our Muscles, 

Bones, and Other Tissues 

The blood as we see it when we cut ourselves, is a red 
fluid. But if we look at it through a microscope, we find 
that the blood looks 
yellow and consists of a 
straw-colored fluid with 
many round, yellowish 
bodies and a few larger 
colorless bodies. The 
round, yellowish bodies 
are called the red cor¬ 
puscles of the blood. 

The others are called the 
white corpuscles. The red 
corpuscles give the blood 
its color. 

When digested food 
passes through the walls 
of the intestine and en¬ 
ters the blood, it becomes 
part of the fluid of the 

As seen through a microscope. The 
blood. When the blood rec j corpuscles carry oxygen from the 

passes through the lungs, lungs to a11 P arts of the body. The white 
, , , corpuscles destroy microbes. 

oxygen is taken up by 

the red corpuscles from the air in the lungs. The blood 
then carries the food and the oxygen to all parts of the 

39 



Red and White Corpuscles of the 
Blood 






































40 PHYSIOLOGY, HYGIENE, AND SANITATION 


body, where they are used either to do work or to build 
up tissues. 

The food and the oxygen are used by the muscles when 
we walk and run. They are used by the stomach when it 
works and churns the food. The glands of the stomach 
make the gastric juice out of them. The saliva with 
which we moisten our food when we chew it, is made out 

of the food and the oxygen carried 
by the blood. When we think and 
when we work examples in arith¬ 
metic, our brains use up some of the 
food and oxygen. The heart itself 
as it pumps the blood gets the power 
to do it by using some of the food 
and oxygen in the blood. 

Some of the food in the blood goes 
to make muscle and bone. In this 
way our bones and muscles get larger 
and we grow. It is by changing the 
food in the blood to muscle, bone, 
and other tissue that the boy can 
grow to be a man and the girl to be 
muscle cells and carry a woman. 

blood to them to feed Qf course all the tissues, even the 
them when they work. 

bones, have to have water or they 
would become dry like paper. In fact we can get along 
without food longer than we can without water. We 
get the water we need just as we do our food. Most food 
contains some water. Then we drink some. We really 
should drink a great deal. 

When we drink water it passes into the stomach just 
as food does. Then it goes from the stomach into the 



Voluntary or Striped 
Muscles 


Showing how the blood 
vessels extend to the 















THE BLOOD 


41 


intestine. The water passes through the walls of the in¬ 
testine with the digested food and enters the blood. Then 
the blood carries it to all parts of the body. 

Some of the water in the blood is given off in the lungs 
to the air we breathe. If you blow your breath against 
a cool looking-glass you can see the moisture collect on 
it. This is water which the blood gave off to the air in 
the lungs. In winter when it is cold you say you can see 
your breath. This is the moisture you see in the air 
breathed out from the lungs. 

In warm weather the blood gives off some of its water 
through the skin. That is what is happening when you 
perspire. If you perspire a great deal the blood may lose 
a lot of water, then you get thirsty and go and take a 
drink. When you get thirsty it is the blood saying it 
wants more water. 


Questions 

1. What does blood look like when you cut your finger? 

2. What does blood look like when seen through a microscope? 

3. What does the blood carry to all the tissues and organs of 
the body? Where does it get the food it carries? Where does it 
get the oxygen? 

4. What part of the blood gathers oxygen from the lungs? 

5. What do the tissues and organs of the body do with the 
food and oxygen carried to them by the blood? 

6. What would happen to the tissues and organs if the blood 
did not carry water to them? 

7. How does the water we drink get to the blood? 

8. When on a cold day you can see your breath, what is it you 
see? 

9. Where does the water come from when you perspire? 

10. What does it mean when you are thirsty? 


CHAPTER VIII 


The Lungs and Why We Breathe 

You have learned that the organs and tissues of the 
body have to have food so they can do the things each 
has to do. The muscles need food so they can contract; 
the heart needs food so it can pump the blood. The 
organs and tissues also need what is called oxygen. They 
can use the food only if they have oxygen to combine with 
it. 

We get oxygen from the air when we breathe. The air 
is made up of oxygen and nitrogen and small amounts of 
other substances, all in the form of what we call gases. 
Usually we cannot feel the air. However, when the air 
moves rapidly, as when the wind blows, we do feel it. 
A wind is simply air moving rapidly. There are other 
kinds of gases of which you know something. There is 
the gas which is used in gas stoves for cooking. This 
same gas is sometimes used for heating and lighting 
houses. It is usually made from coal and is not good to 
breathe. In fact it makes us sick if we breathe much of 
it, and it may even kill us. It is very poisonous. Then 
there are the gases with which balloons are filled. These 
are all different from the air. 

One fifth of the air is oxygen gas, and about four fifths 
are nitrogen gas. The body does not use the nitrogen in 
the air, but it is not poisonous and it does no harm to 
breathe it. The air surrounds the earth. It extends up 


THE LUNGS AND WHY WE BREATHE 


43 


from the earth for many miles. So we really live at 
the bottom of an ocean of air. Although the air extends 
up from the earth many miles it becomes thinner and 



The Lungs in the Upper Part of the Body 

This is where the air goes when we breathe it in. It is here the blood 
gets the oxygen which it carries to all parts of the body. The lower part 
of the body shows the intestines. 


thinner as one leaves the earth. If one goes up in a bal¬ 
loon, when he gets up about two miles the air is enough 
















44 


PHYSIOLOGY, HYGIENE, AND SANITATION 


thinner so that he notices it, and five miles up it is so thin 
that there is hardly enough to breathe. But down on the 
earth there is plenty of air, and we breathe it all the time 
and seldom think about it. 

The organ with which we breathe is called our lungs. 
Our lungs fill up most of our chests. When you take a 

deep breath the chest moves out 
and gets larger. The lungs contain 
many little spaces which fill with air 
when we breathe. The air goes in 
through the nose, then down past the 
throat and through the windpipe. 
The windpipe is called the trachea. 
It branches in the lungs like the 
branches of a tree. At the ends of 
the smallest branches are the air 
spaces or cells, just as the leaves of 
a tree are at the ends of the smallest 
branches. 

We breathe by making our chests 
large, then small. When we make 
our chests large, the air flows in 
through the nose and windpipe and 

fills the air spaces of the lungs. 

The Back Bone or Wb en we ma ^ e our chests small, 
Spinal Column, the 

Ribs, and the Hip Bones the air is forced out of the lungs 
The lungs are shown through the windpipe and nose. As 

in the chest protected by we breathe, the air flows into and 
the ribs. 

out ol the lungs. 

Now all through the lungs in between the air spaces are 
blood vessels filled with blood pumped there by the heart. 
The walls between these blood vessels and the air spaces 









THE LUNGS AND WHY WE BREATHE 


45 


are very thin, and the little red blood corpuscles take up 
from the air in the lungs some of its oxygen. The cor¬ 
puscles take up very little of the nitrogen in the air, but 
much of the oxygen. While the corpuscles are taking up 
the oxygen, the blood gives off certain waste products 
which it needs to get rid of. So the air that we breathe 
out of our lungs has less oxygen than when we breathed 
it in, and it also carries off waste products from the blood. 
The air gives oxygen to the blood and takes away waste 
products. 

When the blood goes to the lungs it is dark and has 
very little oxygen, but when it leaves the lungs and goes 
back to the heart it is bright red and carries much oxygen. 
The heart then pumps this bright red blood with its oxy¬ 
gen to all parts of the body, where the oxygen is used by 
the organs and tissues just as food is. When the oxygen 
in the blood is used up, the blood again becomes darker 
in color and returns to the lungs for more oxygen. 

We can live for many days without food, and we can 
live for several days without water, but we can live only a 
few minutes without air. The oxygen of the air is more 
important to us than either water or food. 

Questions 

1. What do the organs and tissues have to have besides food and 
water? 

2. What does the air consist of? 

3. What is oxygen? How much oxygen is there in air? What 
other gas does air contain? 

4. How deep is the ocean of air which surrounds the earth? 

5. Can you see the air? Can you feel it? What is a wind? 

6. If you were to go up in a balloon, what would happen when 
you got up five miles in the air? 


46 PHYSIOLOGY, HYGIENE, AND SANITATION 

7. In what way do the body tissues and organs use oxygen? 

8. How does the body get the oxygen it needs? 

9. What can you tell about how we breathe? How are the lungs 
made to fill with air? How is the air forced out of the lungs? 

10. How does the blood take up oxygen from the air in the lungs? 
What do the red blood corpuscles do? 

11. What does the blood give off in the lungs? 

12. In what way is the air we breathe out of our lungs different 
from the air breathed in? 

13. What change takes place in the blood as it passes through 
the lungs? What is the change in color? What does the blood 
carry away from the lungs? 

14. How long could we live without food? How long without 
water? How long without air? 


PART II 


Personal Hygiene, or How to Keep Well and 

Live Long 






CHAPTER IX 


Food — Why We Eat and What to Eat 

When boys and girls grow, their bodies increase in size. 
A young baby weighs eight or ten pounds, while a boy in 
high school may weigh 150 pounds, and a girl 130 pounds. 
This increase in weight of more than one hundred pounds 
is possible because our bodies have the power of changing 
food into bone, muscle, and blood; yes, and into brain 
and heart too. 

As long as we live the organs and tissues of our bodies 
are working. The heart continues to beat all the time, 
the lungs never stop breathing, the liver is always at work, 
and so it is with all the tissues and organs. When they 
stop working, our bodies die. But to do work requires 
energy. The body gets its energy from the food we eat. 
Some of our food is consumed in the body, really burned 
up much as coal or wood is burned in a stove, and in 
being burned it gives off energy and heat. The energy 
gives us the power which makes it possible for our hearts 
to beat and our lungs to breathe and our legs to walk, 
just as the coal burned under the boiler of a locomotive 
gives off the energy which pulls the train. The heat 
given off as our food is burned up keeps the body warm. 

So you see the reasons we eat are: 

First — To give us food which the body can make into 
bone, muscle, and blood so we can grow to full size. 

Second — To give us food which can be burned up in 

49 


50 PHYSIOLOGY, HYGIENE, AND SANITATION 


the body and furnish energy to the heart, lungs, and 
muscles, and in fact to all the tissues and organs; and 

Third — To give us food which can be burned up in the 
body, and in being burned will give off heat to keep the 
body warm. 

The food of children should consist of the kinds that 
will make their bodies grow, so that they will become 
strong, healthy men and women. The food of grown men 
and women should consist of the kinds that will furnish 
their bodies enough energy and heat and keep them 
strong and healthy. Children who have eaten the kinds 
of food that properly nourish the body while they are 
growing will become stronger men and women and will 
live longer than children who do not. 

What foods contain. — Most foods contain much water. 
Vegetables and fruits contain a great deal of water. Even 
meat and eggs have considerable water in them. Milk is 
about seven eighths water. However, it contains less 
water than many of the vegetables and is an excellent and 
important food for both growing children and adults as we 
shall see later. 

The parts of food not water consist mainly of substances 
called proteids, carbohydrates , and fats. They also contain 
substances called inorganic salts and vitamins. 

Proteids. — Proteids are substances which are used 
chiefly to build up the body and make tissue. They 
build up the body when it is growing and also renew the 
tissues that are used up in work and play. Milk, eggs, 
and meats contain more proteids than other foods. Peas 
and beans contain considerable proteid. Cereals such as 
wheat and corn have some. Many other foods contain 
small amounts. There are many different kinds of pro- 


WHY WE EAT AND WHAT TO EAT 51 

teids. Those in meat are not the same as those in milk. 
Those in cereals are still different. Some are much better 
than others for building up the body and making it grow. 
Some of all of them are useful and give to the body some¬ 
thing it needs. For supplying to the body the pro teids 
it needs, liver and sweetbreads are better than beefsteak 
and roasts. But the proteids of milk and eggs are the most 
useful of them all and the most necessary. The food of 
growing boys and girls should consist in part of milk and 
eggs — a quart of milk and at least one egg a day. 

Carbohydrates. — Carbohydrates are such substances as 
sugar and starches. They are used by the body mainly 
to burn up and produce heat and energy. They are used 
by the body but little to build up tissue or to make it 
grow. Their chief purpose is to supply the fuel needed to 
keep the body warm and to supply the energy needed by 
the organs in doing their work, by the heart in its con¬ 
tinuous beating, and by the muscles we use in work and 
play. 

Much of the solid part of vegetables, fruits, and cereals 
consists of carbohydrates. Wheat, corn, rice, beets, and 
potatoes contain large amounts. A considerable part of 
the solids of milk is carbohydrates in a very useful form. 

Fats. — The fats contained in food are butter, olive oil, 
cottonseed oil, lard, the fats on meat, and the oils in nuts 
and seeds. The fats serve the same purpose in food as 
do the carbohydrates, that is, they are burned up to yield 
heat and energy. Some fats are useful in the food. Butter, 
which is the fat from milk, is especially suitable for use 
by the body and may either be eaten as butter on bread 
and on vegetables or taken as a natural part of milk. 

Inorganic salts. — To allow it to grow, and to build up 


52 PHYSIOLOGY, HYGIENE, AND SANITATION 



Skimmed Milk 


the tissues, and to enable the various organs to work prop¬ 
erly, the body needs a constant supply of such substances 
as iron, calcium (lime), iodin, potassium, sodium, mag¬ 
nesium, phosphorus, and sulphur. These are called in¬ 
organic salts. It needs 
only small amounts of 
these, but it must have 
them or the body will 
not grow properly. If 
we do not get enough 
of these substances in 
our food, we shall not 
be healthy and strong. 
Some of these sub¬ 
stances are necessary 
to build up the bones 
of the growing boy and 
girl. All are necessary 
to maintain health. 

Most foods contain 
small amounts of some 
of these substances. 
Milk contains most of 
them and has particu¬ 
larly large amounts of 
These fat globules are really little masses of calcium (lime). If we 

do not drink milk, we 
are very likely not to get enough calcium to keep our 
bodies in the best condition. Some of these substances 
not contained in sufficient amount in milk, meat, and 
bread, are contained in vegetables, particularly the leafy 
vegetables such as lettuce, spinach, cabbage, and cauli- 



Milk 



Cream 

Fat Globules in Milk and Cream 










WHY WE EAT AND WHAT TO EAT 


53 


flower. The best way to get all the inorganic salts we 
need is to drink plenty of milk and eat lettuce, spinach, 
and other vegetables. 

Vitamins. — ATtamins are substances necessary to the 
body. Without them the body cannot use properly the 
other foods, nor can it grow. Without them we cannot be 
well or strong no matter how much other food we eat. 
We need them only in small amounts, but we need them 
very much. 

As yet we do not know a great deal about vitamins 
except that they are contained in certain foods and not 
in others. The foods which contain the vitamins we need 
are milk, butter, eggs, lettuce, spinach, oranges, apples, 
cabbage, carrots, and onions. Many other foods contain 
vitamins in smaller amount. Many foods contain none. 

The easiest and best way to get the vitamins we need 
to make our bodies grow and to keep us healthy and 
strong, is to drink plenty of milk and to eat vegetables 
such as lettuce, spinach, and cabbage, and some fruits, 
such as apples and oranges. 


Questions 

1. What happens to our bodies as we grow? 

2. Out of what does the body make itself larger as it grows? 

3. From what do the organs of the body get their energy to 
keep them working? 

4. What does food furnish to the body besides energy? 

5. What keeps the body warm? How? 

6. What are the three reasons why we eat? 

7. What kind of food do growing boys and girls need? Why? 

8. What substances do foods contain? 

9. What use does the body make of proteids? 

10. What foods contain proteids? 


54 PHYSIOLOGY, HYGIENE, AND SANITATION 


11. Are there many different kinds of proteids? Which foods 
contain the most important proteids? 

12. What are carbohydrates? 

13. What use does the body make of carbohydrates? 

14. What foods contain carbohydrates? 

15. Name some of the fats used in foods? 

16. What use does the body make of fats? 

17. Name some of the inorganic salts the body must have. 
Where does the body get these substances? 

18. Does milk contain many of the inorganic salts the body 
needs? Which one does it contain in largest amount? 

19. Why should one’s food consist in part of leafy vegetables? 

20. How can we be sure to get all the inorganic salts our bodies 
need to keep them in good condition? 

21. What do you know about vitamins? 

22. What foods contain the vitamins the body needs? 


CHAPTER X 


Food — Why We Eat and What to Eat ( Continued ) 

Food for boys and girls. — From what we have learned 
we see that the purpose of food is to furnish the body the 
substances it needs to build it up and make it grow, the 
substances it needs to burn up and produce heat and 
energy, and certain substances which are necessary both 
to cause growth and to make all the organs and tissues 
work properly and keep us in health. 

We need proteids, carbohydrates, fats, inorganic salts, 
and vitamins. In some ways the most important, and the 
ones we are most likely not to get enough of, are vitamins 
and inorganic salts. No one food contains all of these we 
need. Milk contains most of them and if we were to eat 
only one food, the one we would get along on best is milk. 
Milk contains proteids, carbohydrates, fats, many of the 
inorganic salts, and some of the most important vitamins. 

The foods which will furnish us with the necessary sub¬ 
stances we are most likely not to get enough of are milk, 
eggs, vegetables such as lettuce, spinach, and cabbage, and 
fruits like oranges, grapefruit, and apples. But to give 
the body all the many foods it needs we should also eat 
other things as well. We should eat some of the grains 
or cereals such as wheat, corn, and rice. We get wheat 
in white bread and in some of the so-called breakfast 
foods. We get corn in corn bread and Johnny cake. 
Rice is usually eaten boiled or in pudding. We can get 

55 


56 PHYSIOLOGY, HYGIENE, AND SANITATION 


many of the proteids we need in peas and beans and in 
eggs and meat. Eggs are better than meat. The fats we 
get in butter and in milk and some in meat and in 
other foods. The carbohydrates we get in milk, bread, 
and vegetables. Potatoes consist mostly of carbohydrates 
and water. The vitamins and inorganic salts will be got 
chiefly from milk, butter, the leafy vegetables, and fruits. 



CHEESE (FULL CREAM) 




Shows the Relative Proportions oe Proteid, Carbo¬ 
hydrate and Fat in Well-known Foods 

The important things for boys and girls to eat in addi¬ 
tion to other food, if they wish to grow as they should and 
be healthy and strong, are milk, leafy vegetables such as 
lettuce, spinach, and cabbage, bread and cereals, and 
fruits. They may eat of the other foods, but they are of 
less importance. 

Preparation of food. — We eat to feed our bodies. If 
our food tastes good and we enjoy eating it, so much the 
better. Our food should be made to taste as good as 























WHY WE EAT AND WHAT TO EAT 


57 


possible, but nothing should be done to it which will 
make it harder to digest; that is, harder for the body to 
use it. The cooking and preparation of food should make 
it more easily used by the body or more pleasant to eat, 
but never harder to digest. 

Boiling rice and potatoes and most other vegetables 
makes them taste better and at the same time more easily 
used by the body. The same is true of making flour into 
bread and cooking it. These foods all contain large 
amounts of starch, which is changed to a more easily di¬ 
gested form by the heat in cooking. All cereals and 
vegetables such as potatoes, beets, and turnips contain 
considerable starch and are usually cooked by boiling in 
water on top of a stove or by baking in an oven. 

Sometimes people put foods in fats such as butter or 
lard or the fats from meat and cook them on top of the 
stove. This is called frying. When food is cooked in this 
way it is likely to become soaked in fat and greasy. While 
butter is a good food eaten in moderate amount, food 
that is soaked in fat and is greasy is usually not a good 
food. It is often very hard to digest. Food should not 
be soaked in grease when it is cooked. 

Making bread is simply one way we have of preparing 
the cereals so they will be pleasanter to eat and at the 
same time easier to digest. Wheat grain would be hard 
to chew and not very pleasant to eat. But grind it up 
fine into flour and make it into bread and we have a food 
we all like and which the body can digest and use easily. 
You would not care to eat much whole corn. But grind 
it up into meal and make corn bread and we have a pleas¬ 
ing food. 

The simplest way of preparing the grains or cereals for 


58 PHYSIOLOGY, HYGIENE, AND SANITATION 


food is to make porridge. Ground wheat, called cream of 
wheat, or ground corn, called corn meal, or crushed oats, 
called rolled oats, are boiled in water to make porridge. 
This eaten with milk or cream is a very good food. 

Making cakes, cookies, pies, and tarts is also preparing 
food in a form pleasant to the taste. They all consist of 
wheat flour mixed with butter or some other fat, and sugar, 
and then cooked. Pies and tarts have fruit or jelly added. 
They are all made of foods we should eat, but usually 
have so much fat and sugar in them that we should not 
eat much of them. Fie crust usually has so much fat in 
it that it is like fried food and is hard to digest. Cakes 
are likely to have so much sugar in them that they are 
very sweet, and very sweet food is not good. It takes 
away our appetite and makes us not want to eat the food 
we really need and our bodies should have. We should 
eat only small amounts of cake or pie, because we need 
the other foods so much more. 

Lettuce and celery and fruits are usually not cooked. 
They are better foods eaten raw. In fact, we get the most 
good from them only when we eat them uncooked. Milk 
also does not need cooking if it is known to be good milk. 
Milk is not only one of the best foods but requires less 
preparation than most. 

The cooking of food is simply preparing cereals, vege¬ 
tables, and meats in such a manner that they will be easy 
to digest and pleasant to eat. 

Foods growing boys and girls should avoid. — In cook¬ 
ing and preparing food we should make it taste good and 
look attractive. In our efforts to do this, however, we 
should not forget that the purpose of food is to nourish 
the body. No matter how good a thing tastes or how at- 


WHY WE EAT AND WHAT TO EAT 


59 


tractive it looks, if it has been so prepared that it is hard 
to digest it is not good, and its preparation and cooking 
have been a failure. 

Pastries. — Pies and other pastries often have so much 
butter or lard in them that the crust is full of these fats 
and is hard to digest. Most pastries are hard to digest 
and should be eaten only in small amount. 

Fried food. — Cooking food in hot fat is called frying 
it. Some food substances can be cooked in this way with¬ 
out becoming soaked in the grease, but usually fried foods 
are grease-soaked and are used by the body only with 
great difficulty. As a rule fried foods should be avoided 
as much as possible. 

Pickles. — Pickles have little or no food value. They 
are eaten with other things because of their taste, that is, 
to make the food taste better. Things eaten in this way 
to flavor or give taste to food are called condiments. 
Eaten in small amount they are not harmful, but boys 
and girls should avoid eating much of them. Catsup and 
chili sauce are also condiments and should be eaten spar¬ 
ingly. 

Tea and coffee. — Tea is made by pouring boiling water 
over tea leaves, and coffee is made by pouring hot water 
over ground coffee beans. Both tea leaves and coffee 
beans have in them a drug called caffein, which is dis¬ 
solved out by the hot water and is contained in tea and 
coffee as prepared for drinking. Caffein even in small 
amounts makes the heart beat faster, keeps one from 
sleeping, and tends to make people restless and sometimes 
excitable. Tea and coffee have no food value. They do 
not nourish the body. They throw extra work on the 
heart, and keep people from getting as much rest as they 


6o PHYSIOLOGY, HYGIENE, AND SANITATION 


should. Boys and girls who wish to have good health 
and to have their bodies grow should not drink either tea 
or coffee. 

Tobacco. — While we are talking about tea and coffee, 
we should perhaps speak also of tobacco. Tobacco is not 
a food, of course, and is not taken with food. However, 
some people chew it, and many persons smoke after eating. 
We said how in drinking tea and coffee people took into 
their bodies the drug caffein. In smoking people take into 
their bodies the powerful drug nicotine and certain gases 
from the burning tobacco. These are all especially harm¬ 
ful to growing boys and girls. Nicotine lessens the desire 
for food. It interferes with the proper action of many of 
the organs and tissues, and thus lessens growth. If a 
growing boy smokes he will not do as good work in school 
nor do as well at games as he would if he did not. A boy 
who wants to do well at school or to grow to be as big and 
strong as possible must not use tobacco. 


Questions 

1. What can you say of the kinds of food a growing boy or girl 
needs most? 

2. What should be the purpose of cooking and preparing food? 

3. Why are rice, potatoes and vegetables cooked before being 
eaten? What does the heat in cooking do to the starches in these 
foods? 

4. What can you say about cooking food by frying it in grease? 

5. Does bread taste better than wheat would? Why is wheat 
ground into flour and made into bread before it is eaten? What is 
done to corn to make it a more pleasant and more easily digested 
food? 

6. What is the simplest way of preparing the cereals for food? 

7. How do cakes and cookies differ from bread? 


WHY WE EAT AND WHAT TO EAT 


61 


8. What foods are best eaten uncooked? 

9. Why should one not eat much of cakes, cookies or pies? 

10. Why are fried foods usually hard to digest? 

11. What can you say about the eating of pickles and catsup? 

12. How is tea made? How is coffee made? 

13. What do both tea and coffee contain? 

14. What effect on the body do tea and coffee have? Are they 
of any use as a food? 

15. Why should growing boys and girls not drink coffee or tea? 

16. What poison is contained in tobacco? How does this poison 
get into one’s body? 

17. What is the effect of nicotin when taken into the body? 

18. Why should growing boys or girls not use tobacco? 


CHAPTER XI 


Why We Drink and What to Drink 

Two thirds of the weight of the body is water. The 
blood contains water. All the organs and tissues, even 
the bones, contain water. The body cells, that is, the 
little cells which make up the organs and tissues, are them¬ 
selves made up in large part of water, just as an orange 
or a lemon or a melon is. The saliva with which we mois¬ 
ten our food when we chew it is mostly water. So is the 
gastric juice which the stomach secretes to help digest our 
food. 

The body is giving off some of its water all the time. 
The air which we breathe out of our lungs carries with it 
some water in the form of vapor. The body is losing 
water constantly through the skin in the form of perspira¬ 
tion. On a hot day we lose a great deal in this way and 
then we notice it as sweat. But usually the water given 
off by the skin evaporates as fast as it forms, and we do 
not notice it. The body also loses water in other ways. 

In all, the body loses two or three quarts or even more 
water a day. We have to take into our bodies just as 
much water as we lose, for if we do not, the blood will 
become too thick and the body cells will not have all the 
water they need. The body gets water in two ways, from 
the food we eat and from the things we drink. 

Practically all foods contain some water. Fruits and 
vegetables contain a great deal. Many of them are almost 

62 


WHY WE DRINK AND WHAT TO DRINK 63 


all water. Even apparently dry foods such as bread and 
crackers contain a little. But we do not get all the water 
we need from foods. That is why we have to drink. 

The purpose of drinking is to furnish the body with 
enough water. Usually we drink plain clean water. Some¬ 
times we put lemon juice and sugar in it and then we call 
it lemonade. Sometimes ginger and sugar are put into it, 
and it is put up in bottles. Then we call it ginger ale. 
Sometimes other flavoring is put in, and we call it pop, or 
soda water. Some people drink tea and coffee. These are 
simply hot water into which tea and coffee have been put. 
They contain a drug called caffein which is to some extent 
a poison and is not needed by the body. Children espe¬ 
cially should not drink tea or coffee, and most people would 
be better off without it. 

The best way to give the body the water it needs is by 
drinking pure water. Pure water is clean and clear and 
has no taste or smell. If it has a taste or smell, it is be¬ 
cause there is something in the water which should not be 
there. 

When the body has lost some of its water and needs 
more we feel thirsty. The feeling of thirst is the body 
letting us know that it needs more water. 


Questions 

1. How much of the body’s weight is water? 

2. What can you say about the water lost by the body through 
the lungs and skin? 

3. How much water does the body lose in a day? 

4. What would happen if the body kept losing water and was 
not given more? 

5. How does the body get the water it needs to make up for 
what it loses? 


64 PHYSIOLOGY, HYGIENE, AND SANITATION 


6. Why does one drink more water in warm weather than one 
does when it is cold? 

7. What can you say about the water in foods? 

8. What is the best way to give the body the water it 
needs ? 

9. What does it mean to be thirsty? What might happen if the 
body did not let one know when it needed more water? 


CHAPTER XII 


The Kind of Air We Should Breathe 

You have learned how we breathe air into the lungs so 
that the blood can get oxygen to carry to all the organs 
and tissues of the body. You have also learned that the 
blood gives off in the lungs certain waste products which 
are carried off by the air we breathe out. 

The best air is pure air. Like water, air should be 
clean and should have no odor. If it contains smoke or 
dust, these get into the lungs, and they are not good for 
them. A coal miner’s lungs get dark and sometimes al¬ 
most black from the constant breathing of the coal dust. 
A stone-cutter may get into his lungs fine stone-dust 
which will in time harden his lungs and do them damage. 
Even street dust in the air is bad for us, for although most 
of it is stopped in the nose as we breathe in the air, some 
of it may find its way down into the lungs. 

Some people cannot breathe air containing the pollen of 
certain plants without getting a condition resembling a 
cold in the head called “hay fever.” Some plants, such 
as rag weed and hay, give off to the air great quantities 
of pollen when their flowers are in bloom. This pollen is 
like a very fine dust and usually cannot be seen in the air, 
but if some people breathe it they quickly develop hay 
fever or asthma. However, it does little or no harm to 
most people. 

You have probably heard that outdoor air is better for 

65 


66 PHYSIOLOGY, HYGIENE, AND SANITATION 


us than air indoors. Let us see if from what we have 
learned we can tell why this is so. We know that the body 
is always warm and that it is constantly giving off heat 
and also water in the form of perspiration. We know also 
that while the air we breathe into our lungs may be cool 
and dry, the air we breathe out is warm and full of mois¬ 
ture. Because this is so, if we sit quietly in a room with 
the doors and windows closed, the air about us becomes 
warm and moist. If there are many people in the room, 
all the air becomes warm and moist. Then we feel less 
^comfortable and may get drowsy, because when the air 
about us is warm and moist and quiet, the body cannot 
so well get rid of the heat that it is all the time making. 
The body is at all times making heat within itself as it 
uses up, or really burns up, the food we have eaten. The 
heart, as we learned, makes heat as it beats. The lungs 
make heat as we breathe. The stomach and liver and 
muscles all make heat, and the body has to get rid of all 
this heat or we become too warm. 

You have noticed that as long as the room is cool, the 
air does not seem close and you do not get drowsy. Or if 
in a room in which the air has become what we call close, 
— that is, warm and moist, — an electric fan is started, 
you feel better at once. This is because the fan keeps the 
air moving so that the warm moist air about our bodies is 
constantly blown away and the body can better get rid 
of its heat. If the windows and doors are opened so that 
the outside air blows in, we also feel better, and the air 
seems fresh, as we call it. All the moist warm air is blown 
away so that our bodies are constantly bathed in cooler, 
drier air, and we get rid of the heat of the body so much 
the better. 


THE KIND OF AIR WE SHOULD BREATHE 67 

The outdoors is so much bigger than a room, and the 
outdoor air is usually being moved about by at least some 
breeze, even if it is so gentle we cannot feel it, so that 
outdoors warm moist air does not collect about us but is 
constantly carried away. As a result, the body can get 
rid of its heat much better when we are outdoors. 

You have noticed at times in summer when it is hot 
and even the air outdoors seems perfectly still, how hot 
and uncomfortable you feel. Then if a breeze comes up 
how much more comfortable you become! 

The outdoor air is better for us, because the breezes and 
constant movement of the air carry away from us the heat 
and moisture we give off and keep our bodies bathed in 
cooler and drier air. This makes it easier for the body to 
give off the heat it is constantly making and must get rid of. 

The air we breathe should be clean. Outdoor air is best. 


Questions 

1. Why do we breathe air? 

2. What kind of air is best? Why should the air we breathe 
be clean? 

3. Why should the air we breathe not contain smoke or dust? 

4. What happens to the lungs of a coal miner? 

5. What may happen to the lungs of a stone cutter? 

6. What causes hay fever? 

7. What happens to the air of a room in which there are many 
people? How does it make one feel? 

8. Why does the breeze from an electric fan make one feel 
more comfortable in hot weather? 

9. Why is outdoor air better for us than indoor air? 

10. Can you tell why people who live outdoors most of the time 
usually have better, stronger bodies than do people who spend most 
of their time indoors? 


CHAPTER XIII 


How Work and Play Train the Body 

You have learned about the body and how it can be 
trained to do many things. You have learned how the 
muscles and the brain can be taught to work together so 
that we can swim, skate, and play ball. We teach the 
body to do things by doing them. Some of the things we 
do we call play and some we call work. Usually the things 
we like to do we call play, and the things we do not like 
to do we call work. There is really very little difference 
between work and play except that we like to do some 
things better than others. 

The carpenter makes boxes and builds houses to earn 
money and thinks of it as work. The school boy makes 
boxes and builds little houses and thinks of it as play. 
The professional baseball player plays ball every day to 
earn money, and to him it is work. The boy plays ball, 
and it is play — not work. A girl will be asked by her 
mother to take care of her baby sister, and she thinks of 
it as work, but she will play with her dolls and pretend 
they are babies she is taking care of, and to her it is play. 
So whether doing a thing is work or play depends on how 
we think of it. If we think of work as play, it becomes 
play. If we think of play as work, it becomes work. 

Whether we work or play we are training the body to 
do things, provided we work and play properly. The body 
needs the training it gets by doing the things we call 

68 


HOW WORK AND PLAY TRAIN THE BODY 69 

work, just as much as it does the training it gets by doing 
the things we call play. 

Boys and girls in school usually think of their studies 
as work, but in getting their lessons and doing their 
school work they are teaching their brains to know many 
things and especially how to think correctly. Geography 
teaches us about the earth and its land and seas and about 
the various countries and the people who live in them. 
History teaches us what people did in the past. Grammar 
teaches us how to speak and write correctly. Nature 
study and botany, geology and astronomy teach us about 
the world in which we live. We certainly all want to know 
just as much as we can about this world in which we 
must spend our lives. Arithmetic and algebra teach us 
how to work out certain kinds of problems which will be 
very useful to us, and especially do they train the brain 
to reason. 

But to get the most good out of work and play, what¬ 
ever we do, we should do just as well as we can. Each 
time we do a thing we should try to do it better than we 
ever did it before. In this way we train the body to do 
things better and better. If we do not do things well, we 
teach the body bad habits. Unless we train the body to 
do things constantly better, it is not getting the benefit 
it should from the work or the play. If we try each time 
to do our work, whatever it is, better than we did it the 
time before, it becomes a game, and then it is play. 

There is another reason why we must all do work. 
There is much work to do if we live as we want to live. 
Somebody must prepare and cook our food. Somebody 
must make our clothes. Somebody must build our houses. 
Somebody must make our roads. If we are to have food, 


70 PHYSIOLOGY, HYGIENE, AND SANITATION 

clothes, houses, and roads, each one must help in some 
way. Tramps try to get along without doing work, and 
try to have others do all their work for them. But who 
wants to be a tramp? 

For the boy and girl all work and play should be a 
game and the object of the game should be to train the 
body to do things well. 

Questions 

1. How do we train our bodies to do things? 

2. How does one learn to skate or swim or do problems in arith¬ 
metic? 

3. What is the difference between play and work? Is building 
a toy house play to a boy? Is building houses play to a carpenter? 
What is the difference? 

4. What do work and play do for our bodies? 

5. Do you study history at school? Do you think of it as work 
or as play? 

6. Do you read story books? Do you think of reading them as 
play or work? 

7. How can work be made play? 


CHAPTER XIV 


The Need for Sleep 

When we work or play for a time we become tired. 
When we use actively the muscles of our legs or arms, the 
muscles in working use up the food which the blood car¬ 
ries to them, and in doing this there are left in the muscles 
waste products, just as when you burn coal in a furnace 
smoke is given off and ashes are left. Smoke and ashes 
are waste products. The muscles in working not only use 
up food carried to them by the blood, but the muscle cells 
use up also part of their own substance. For this reason 
after they have worked awhile they begin to refuse to 
work, because they have used up a large part of their 
material. The muscles are then tired. 

But you know that muscles are controlled by nerve 
cells, and whenever a muscle contracts it is because cer¬ 
tain nerve cells in the brain or spinal cord have sent mes¬ 
sages to the muscle cells and caused them to contract. 
In doing this the nerve cells use up some of their sub¬ 
stance, and after they have worked in this way for a time 
in keeping the muscles working, they too give off waste 
products and become partly worn out and tired. 

Also when we study the brain cells use up part of them¬ 
selves, and after a time become partly exhausted and tired. 
And as the heart keeps beating and the lungs breathing 
all day long, their cells use up food material, give off waste 
products, and become tired. 


71 


72 PHYSIOLOGY, HYGIENE, AND SANITATION 


In this way there accumulate in the body waste products 
which in a sense are poisons, because the tissues and or¬ 
gans, the muscles, the brain, and the heart, cannot work 
well until the body gets rid of them. Then too as we 
work and play during the day the muscles and body organs 
become tired. Then we get weary and sleepy. When we 
get tired and sleepy, it is because the body cells are tired 
and have in them and around them the waste products 
they have formed in working. 

We go to sleep tired and weary. In the morning we 
wake up refreshed. We are no longer tired. We are ready 
again to work and play. Something has happened while 
we were asleep to make this difference. 

While we were asleep the body was perfectly quiet. 
The muscles and brain stopped working. Even the heart 
slowed down and beat more gently and the lungs worked 
less hard and breathed more slowly and easily. While 
the organs and tissues were all resting in this way, the 
body got rid of all the waste products which had been 
formed by the tissue cells during the day. Some of these 
waste products were got rid of through the lungs. The 
blood carried them to the lungs and from there they 
passed out into the air as we breathed. Some of the 
waste products were got rid of through the kidneys. 

Then too while we slept the body cells took up from 
the blood, which flowed slowly around them, the food 
they needed to replace that which they had used up during 
the day. We can think of the tired cell as thin and weary 
at night and plump and refreshed in the morning after a 
good night’s rest. 

We should get enough sleep each night so that the body 
may have plenty of time to get rid of all the waste prod- 


THE NEED FOR SLEEP 


73 


ucts formed during the day and to replace in the cells of 
the nerves and muscles the materials they used up while 
at work and play. If our sleep has been long enough, we 
wake up refreshed, feeling ready for another day’s activi¬ 
ties. If our sleep has not been long enough, we get up still 
feeling tired. 

The body machine does not work well when the blood 
and organs are filled with waste products or when the 
tissue cells are tired and exhausted. Each morning should 
find the body free from the waste products and the cells 
refreshed, plump, and ready for work. To accomplish 
this, boys and girls from ten to fourteen years of age 
require about ten hours’ sleep every night. Some need 
eleven hours. Sleep is even more important than food. 
We can go without food much longer than we can go 
without sleep. Young dogs have gone without food for 
as long as twenty days and lived, but when kept awake 
for five days they died. 

Plenty of sleep is important, especially for growing 
boys and girls. Without enough sleep they will not be 
healthy, nor will they be able to do as good work at school. 
The boys and girls who get plenty of sleep will be the ones 
who will do the better work and do the best at play. 

Questions 

1. When the muscles work what do they use up? What do all 
the organs and tissues use up when they work? 

2. When the muscles in working use up food what kind of 
products are formed? 

3. Why are the waste products formed in the body like the ashes 
left in the furnace when coal or wood is burned? 

4. When a muscle is worked what does it use up besides food 
brought to it by the blood? 


74 


PHYSIOLOGY, HYGIENE, AND SANITATION 


5. What does it mean when a muscle gets tired? 

6. Do nerve cells get tired? Why? 

7. Do the brain cells get tired? What makes them tired? 

8. Can the organs and tissues work well when they are sur¬ 
rounded by waste products? Why not? 

9. Why do we get tired and sleepy? 

10. What does the body do while we sleep? 

11. What do the body cells do while we sleep? 

12. How much sleep does one need? 

13. Is sleep more important to us than food? 

14. Can one do things better at night when tired or in the morn¬ 
ing after a good night’s sleep? Tell why. 


CHAPTER XV 


The Need for Regular Daily Habits 

There are certain things we have to do each day. The 
two principal things we do are to sleep and eat. Other 
important things we do are to wash ourselves and brush 
our teeth. Then too most of us have chores to do at home. 

If we do these things at the same time each day, the 
body gets used to doing them at that time and does them 
more readily and easily. In fact, the body gets so regulated 
to doing them that it will do them almost without our 
thinking about them. 

Going to bed. — If we go to bed at the same time each 
night, our bodies get so that they are always ready for 
bed when the time comes. If we go to bed each night at 
nine o’clock, we soon find that each day as it gets near 
nine o’clock we feel sleepy, and we realize that our bodies 
want to rest and go to sleep, and going to bed becomes 
easy and pleasant. But if we stay up until ten or eleven 
o’clock for several nights, we find then that our bodies 
get out of the habit of going to bed at nine. They forget 
just when their bedtime is and do not seem to know just 
when to be ready for bed. And then instead of our bodies 
telling us when it is time to go to bed, we have to train 
them again to going at the proper time. It is so much 
easier to go to bed when our bodies are trained to going 
at a certain time. Then we fall to sleep much more 
easily and quickly. 


75 


76 PHYSIOLOGY, HYGIENE, AND SANITATION 

Getting up in the morning. — The same thing is true of 
waking up in the morning as of going to bed at night. 
If we get up at the same time each morning, after awhile 
our bodies get so that they will wake up promptly at the 
proper time. If we get up each morning at seven, our 
bodies will soon get the habit of waking promptly at that 
time, and then getting up and washed and dressed is no 
trouble at all. We just do it without thinking. Our 
bodies do it because they have formed the habit. But if 
we get up sometimes at six o’clock, and sometimes at 
seven, and sometimes at eight, our bodies do not learn 
when it is time to get up and do not know when to wake. 
Someone will have to wake us, and even then we will 
probably not feel like getting up, but will want to sleep 
some more. It is much easier to get up at the proper 
time when we do it at the same time each day and our 
bodies get the habit. Then, too, by fixing the time we go 
to bed and get up each day, we can be sure that we get 
the proper amount of sleep, and it is important that grow¬ 
ing boys and girls get enough sleep. 

Eating. — Much the same thing is true of eating as of 
sleeping. We eat three times a day or perhaps four. If 
we eat at the same times each day, our stomachs get used 
to taking in food at these times and are ready for it. 
They do their part in the digestion of one meal and pass 
it along into the intestine, then rest awhile and get ready 
for the next meal. If we eat at the same time each day, 
we soon find that when meal time draws near we are 
ready to eat. We do not get hungry at other times. 
When we get hungry, it is our stomachs saying they are 
ready for food. 

If we eat at different times each day, our stomachs do 


NEED FOR REGULAR DAILY HABITS 


77 


not know when to be ready for food. They find that 
sometimes they are given a new supply of food to digest 
before they have finished with the preceding one, or per¬ 
haps that just as they have finished with one meal and are 
about to rest, they are set to work again. Our stomachs 
then do not know when to be ready for food, their work 
is interfered with, and they cannot take care of the food 
nearly so well. We should eat our meals at the same 
time each day so that our stomachs may get the habit of 
taking care of them in an orderly way. 

Not only the stomach forms the habit of digesting the 
food given to it and passing it on in the alimentary tract 
regularly, but the whole alimentary tract, including the 
intestine, forms the habit of doing its work regularly if 
given an opportunity. The intestine completes the diges¬ 
tion of the food passed into it from the stomach and 
passes on what is left and cannot be digested. This ac¬ 
cumulates in the lower end of the intestine, sometimes 
called the lower bowel. The intestine gets rid of this 
when we have a bowel movement. The body needs to 
get rid of this remains of our food regularly or it will fer¬ 
ment and decompose and do us harm. Just as we have 
certain times for our meals and train our stomachs to ex¬ 
pect food at those times, we should have certain times 
when we empty our bowels, and should train them into 
the habit of getting rid of the waste from our food at 
those times. The bowel will form the habit just as readily 
as the stomach does. To train the bowel, all we have to 
do is to give it an opportunity to empty at the same times 
each day, either when we first get up in the morning or 
after breakfast or after some other meal. But to train 
the bowel, it must be given the opportunity to empty at 


78 PHYSIOLOGY, HYGIENE, AND SANITATION 

the same times each day. It will soon form the habit, 
and our whole alimentary tract will do its work better. 

Washing face and hands. — If when we first get out of 
bed each morning we wash our hands and face, we soon 
get so that we do it without thinking. It becomes a habit, 
and if some morning we should fail to do it we would feel un¬ 
comfortable. We would know that something was wrong. 
We would find that washing our face and hands had become 
a pleasure and was necessary for our comfort. The same 
thing is true of washing our hands before eating our meals. 
We soon get so that we do not like to eat without wash¬ 
ing our hands first, and do not like to handle our food un¬ 
less we are sure our hands have been washed and are clean. 

Brushing the teeth. — In nothing is the advantage of 
doing a thing at the same time each day truer than in 
brushing the teeth. If each morning when we first get up 
and again just before we go to bed we brush our teeth, 
we soon get so we do it without thinking. It is no trouble 
at all. If we fail to do it, we find our teeth miss it and 
our mouths do not feel right. It becomes one of the 
pleasant things we do and one of the things that makes us 
feel comfortable. Those who do not brush their teeth 
regularly do not learn the pleasure of clean teeth. Not 
only that, but teeth that are kept clean last much better 
than teeth that are not taken care of properly. 

How regular habits simplify the things we do. —Train¬ 
ing the body to do things at the same time each day 
causes it to do them much more readily and easily. It 
makes many of them pleasures. The body gets so trained 
it will do them without our thinking about them. It 
makes all the things we have to do easier and we can live 
our lives much happier and better. 


NEED FOR REGULAR DAILY HABITS 


79 


Questions 

1. Name some of the things you do every day. 

2. Do you go to bed at the same time each night? Do you get 
sleepy at the same time each night? 

3. Why should one go to bed at the same time each night? 

4. Do you get up at the same time each morning? Do you have 
to be waked up or do you wake without being called? 

5. Why is it best to get up each morning at the same time? 

6. How many times a day do you eat? Do you always eat your 
meals at the same time? Why should one always eat one’s meals 
at the same time? How does it help the stomach in its work? 

7. Why should one have at least one bowel movement each 
day? How can the bowel be trained to empty itself at regular times? 

8. Why is it best and easiest to do at the same time each day 
the things we have to do daily? 

9. How can the body be trained to do things at the same time 
each day? 

10. Does the body acquire habits readily? Does it acquire good 
habits as easily as bad habits? 

11. What can you say about the habit of washing one’s face and 
hands? Have you acquired the habit of washing your hands before 
each meal? 

12. What can you say about the habit of brushing one’s teeth? 


CHAPTER XVI 


The Skin and Its Care 

The skin is the outer covering of the body. It protects 
the deeper tissues from injury. It keeps out of the body 
germs that would do the tissues harm. It helps keep 
the body cool in hot weather and warm in cold weather. 
Through it the body gets rid of much of its excess heat 
and some of the waste products formed by the muscles 
and organs as they work. The skin is an important 
part of the body, and our comfort and health depend 
upon its being kept in good condition and working 
properly. 

The skin consists of two layers. The outer layer is 
called the epidermis and the deeper layer the dermis. 

The epidermis. — The epidermis consists of many cells. 
The deeper cells are mostly round. The outer cells are 
flat and arranged much like the shingles on a house, but 
they are many layers deep. They protect the body and 
in places become very thick and hard, as in the palms of 
the hands and soles of the feet. The epidermis in the palms 
of the hands becomes still thicker in persons who do much 
work with their hands. The epidermis becomes thickened 
to protect the hands. In children who go barefoot, the 
epidermis on the soles of the feet becomes especially 
thick. This is to protect the feet from injury. There 
are no blood vessels in the epidermis. If there were, 
every little scratch would cause it to bleed. 

80 


THE SKIN AND ITS CARE 


81 


The dermis. — Under the epidermis is the dermis, 
which is also sometimes called the true skin. It consists 
of a tough, strong network of what is called connective 
tissue, in which are many little blood vessels and nerves. 
In it are also the sweat glands and oil glands. The oil 
glands are called sebaceous glands. It also contains the 
roots of the hairs which grow on the body. Have you 
ever seen a fur rug made 
from the hide of an animal? 

The hide of an animal is its 
skin. The fur is the hair. 

The sweat glands. — In 
the dermis or deep layer of 
the skin are the little glands 
called sweat glands. Each 
gland has a duct which ex¬ 
tends up through the epi¬ 
dermis and opens on the 
surface of the skin. These 
are found in the skin of al¬ 
most all parts of the body. 

In some parts, however, they Vertical Section oe the Skin 

are larger and more numerous Shows a sweat gland, oil glands and 

, •, . ,1 • .1 a hair. Notice also the blood vessels, 

than m others, as in the 

palms of the hands and on the forehead. 

These glands secrete and pour out on the surface of the 
skin a clear, colorless liquid called sweat, which is mostly 
water, but contains small amounts of the waste products 
formed by the tissues of the body. These glands are at 
all times secreting small amounts of sweat. However the 
sweat usually evaporates as rapidly as it reaches the sur¬ 
face of the skin so that we do not notice it. It then merely 















82 PHYSIOLOGY, HYGIENE, AND SANITATION 


keeps the skin from getting too dry. When we get warm 
the glands secrete more, and then we can see it as moisture 
on the skin. A person may secrete as much as two or 
three quarts of sweat a day in warm weather. While the 
sweat carries off some waste products from the body, its 
main purpose, as we shall learn later, is to keep the surface 
of the body cool. 

The oil glands. — The deeper layer of the skin also con¬ 
tains glands called sebaceous glands. Like the sweat 
glands these have ducts which pass up through the epi¬ 
dermis and open on the surface of the skin. These glands 
secrete an oily substance which covers the skin and serves 
to keep it from drying. They are especially abundant on 
parts of the body where there is hair, as on the head. 
Their secretion serves to furnish oil to the skin and to the 
hairs so that they will not become dry and brittle. 

The secretion of these glands contains not only oil but 
also some broken-down cells from the glands themselves. 
If the ducts of the glands become blocked so that the 
secretion cannot get out, they sometimes become infected 
and form what are called pimples. 

The hairs. — The skin also contains hairs. The roots of 
the hairs are located in the deeper layer of the skin. Hairs 
are present in the skin of practically all parts of the body 
except the palms of the hands and the soles of the feet. 
On some parts of the body the hairs are long and large, 
as on the head. On most parts of the body the hairs are 
short and fine. 

How the skin protects the body from heat and cold. — 

Our organs and tissues are at all times forming heat as 
they work and burn up food, and at times they form a 
great deal of heat, as when we work or play hard. But no 


THE SKIN AND ITS CARE 


83 

matter how much heat is formed in the body, and no mat¬ 
ter how warm or how cold the weather, the temperature 
of the body remains just about the same. It is chiefly the 
skin and its blood vessels that get rid of the excess heat 
formed in the body. It is also the skin and its blood ves¬ 
sels that keep the body from getting chilled in cold weather. 

As has been explained, the deeper layer of the skin 
contains many small blood vessels. When the body has 
heat that it needs to get rid of, these blood vessels dilate 
and become larger, and as the blood flows through them it 
gives off its heat and becomes cooled. We can see this 
best in the face. When one becomes hot the cheeks 
usually get red. This is because the blood vessels in the 
skin of the face are dilated and full of blood. The blood 
in the vessels is what makes the face red. The blood has 
come to the surface of the body to get cooled. 

When the weather is cold and the body wants to save 
its heat to keep warm, the blood vessels in the skin con¬ 
tract and become small so that very little blood can flow 
through them. In this way the body keeps the blood in 
the deeper tissues and away from the surface so it will not 
lose its heat. If when the weather is cold much blood 
flowed through the skin, it would become rapidly cooled 
and much of its heat would be lost. When the hands 
are exposed to cold they get pale because the blood vessels 
of the skin of the hands have contracted to keep the blood 
from getting chilled and losing its heat. The blood vessels 
in the skin of other parts of the body contract in the same 
way. 

How the skin keeps the body cool in hot weather. — 

When the weather is hot and the skin becomes warm, the 
body would have difficulty in getting rid of its excess heat 


84 PHYSIOLOGY, HYGIENE, AND SANITATION 


if it were not for the help of the sweat glands. These 
glands are located, as we have learned, in the deeper layer 
of the skin, and pour out their secretion, called sweat, on 
the surface of the skin. When the surface of the body 
becomes too warm, the sweat glands become active and 
secrete large amounts of sweat which covers the surface of 
the skin with moisture. This moisture evaporates and in 
doing so cools the surface of the body. Whenever water 
evaporates it takes up heat and cools the surface it is on. 
When one’s clothes are wet they always feel cooler. Sweat¬ 
ing is simply the means the body uses to keep its surface 
cool. As long as the skin is cool, the body can get rid of 
its excess heat. When one has fever, the sweat glands 
secrete but little, the skin becomes dry and hot and the 
temperature of the body may become several degrees 
warmer than it is in health. 

The care of the skin. — We have learned how the sweat 
glands are continually secreting sweat on the surface of the 
skin and how the sweat usually evaporates as fast as it is 
formed. What really evaporates is the water in the sweat. 
The waste products in the sweat do not evaporate, but 
for the most part remain on the skin. We have also 
learned about the oil glands in the skin and how they 
secrete oil containing broken-down gland cells. In this 
way the waste products from the sweat and the oil and 
broken-down cells from the oil glands accumulate on the 
surface of the body unless we wash or rub them off. 

We wash our hands to get rid of the dirt on them that 
we can see, and to keep them free from germs and microbes 
which might get into our mouths when we eat and thus 
do us harm. For this reason we should always wash our 
hands before we eat. For the same reason we should 


THE SKIN AND ITS CARE 85 

keep our finger nails clean. It is a good practice to clean 
the finger nails whenever we wash our hands. 

When we wash our bodies all over we call it taking a 
bath. We bathe our bodies to wash from the skin the 
waste products left by the sweat and the broken-down 
gland cells secreted by the oil glands. It is just as impor¬ 
tant to wash the skin of our bodies as it is the skin of our 
hands, even if our bodies do not show the dirt as our 
hands do. 

Bathing not only keeps the surface of the skin clean, but 
if we rub the skin well with a rough towel it also keeps the 
ducts of all the little skin glands from getting blocked up. 
Rubbing the skin with a rough towel after taking a bath 
is just as important as the bath. The rubbing does the 
skin good and makes it do its work better. 

We should wash the skin of the body and rub it with a 
coarse towel at least twice a week. It is a good plan to do 
it every day if one can. It makes one feel better and is 
good for the skin. 

When one takes a bath he should clean his toenails 
just as he cleans his finger nails when he washes his hands. 
The toenails get dirty just as the finger nails do. 

The hair of the head should be washed from time to 
time, both to clean the skin of the head called the scalp 
and to clean the hair. It should be washed often enough 
to keep the scalp clean and the hair clean too. 

Questions 

1. How does the skin protect the body? 

e. How many layers has the skin? 

3. What is the outer layer called? What is the name given to 
the inner layer? 


86 PHYSIOLOGY, HYGIENE, AND SANITATION 


4. What can you say about the outer layer? Where does it 
often become very thick? 

5. What does the inner or deep layer of the skin contain? 

6. What can you say about the sweat glands? What do they 
secrete? What is its purpose? 

7. What can you say about the sebaceous or oil glands of the 
skin? What do they secrete? What is its purpose? 

8. How does the skin help keep the body warm in cold weather? 
How does it help keep the body cool in warm weather? How does 
sweat cool the body? What do the blood vessels in the skin do when 
the body gets cold? What do they do when the body gets too warm? 

9. Why should one keep one’s hands clean? Why should one 
wash one’s hands before each meal? 

10. Why does one need to wash the skin of one’s body? What 
does rubbing the skin with a rough towel do, especially if done after 
taking a bath? 

11. What can you say about the need for washing the head? 

12. Why should one keep one’s finger and toe nails clean? 


CHAPTER XVII 


The Teeth and Their Care 

When babies are born they have no teeth. However, 
when they are a few months old teeth begin to appear 
through the gums, first in front, and later at the sides, 
so that at about two years of age children usually have 
twenty teeth. These are called the first teeth, or sometimes 
the milk teeth. At six or seven years of age these teeth 
begin to get loose and come out. Usually one tooth 
loosens at a time, and in its place there soon appears 
another tooth. These second teeth that appear are called 
the permanent teeth, because they do not come out, but re¬ 
main with us if we take proper care of them. They are the 
last teeth we shall ever have. When all of the permanent 
teeth develop there are thirty-two. If one should get in¬ 
jured or become decayed so that it has to be taken out, 
no other tooth will grow in its place. As we need teeth 
to chew our food, we should take such care of them that 
they will remain sound and healthy all our lives. 

The structure of the teeth. — The teeth are hard, and 
in this they resemble the bones. Each tooth has a crown, 
which is the part we see projecting above the gums, and 
a root which extends down into the bone of the jaw. 

The outside of each tooth is hard, but in the center it is 
hollow. The central cavity is filled with soft tissue, called 
the pulp. In the pulp are blood vessels and nerves which 
enter at the end of the roots. The hard part of the tooth 

87 


88 PHYSIOLOGY, HYGIENE, AND SANITATION 


consists chiefly of bony material, called ivory or dentin. 
The outside of the crown of the tooth, which is the part 
we see, is covered with a very hard substance called enamel. 
The enamel is the hard substance that protects the teeth 
when we chew food. If it gets broken, the softer dentin 
of the tooth is exposed, and the tooth is liable to decay. 



5 


The Teeth 


A. Section of a single molar, i. Pulp. 2. Dentin. 3. Enamel. 4. 
Crown. 5. Neck. 6. Root. B. Teeth in position in lower jaw. 1. 
Incisors. 2. Canine. 3. Bicuspids. 4. Molars. C. Upper and lower 
teeth on one side. 1. Incisors. 2. Canines. 3. Bicuspids. 4. Molars. 
5. Wisdom. D. Upper and lower incisor, to show gliding contact. 

The teeth have blood vessels and nerves in the pulp of 
their central cavities which (as was said) enter through 
holes in the ends of the roots. The blood feeds the teeth 
the food and nourishment they need just as it does the 
muscles and other tissues. The nerves of the teeth tell 
us when the teeth have been injured just as the nerves in 
our fingers tell us when our fingers are hurt. When we 

















THE TEETH AND THEIR CARE 89 

have a toothache, it is the nerves telling us that we have 
a tooth that has been injured and needs attention. 

Good health makes good teeth. — If our bodies are 
healthy and properly nourished, our teeth will be strong 
and healthy and not likely to become diseased and get 
holes in them. If the body is unhealthy, the teeth are 
likely to be unhealthy. We have explained how the body 
needs in its food certain vitamins and inorganic salts 
found in milk, leafy vegetables, and cereals. If the body 



Shows how Different One looks when 
One loses a Tooth 

does not get these things, the teeth are likely to suffer. 
The health of the teeth depends in a large measure upon 
the health of the whole body. 

Teeth and gums need exercise. — We learned in a 
previous chapter that our muscles and organs all need 
exercise to keep them in good condition and make them 
strong. Our teeth need exercise to keep them healthy. 
The work of our teeth is to chew food. They get their 
exercise in doing this. Food that is tough and requires 
much chewing gives them plenty of exercise, while food 
that is soft, like mush or pudding or soft bread, gives the 
teeth very little exercise. If we eat nothing but soft food, 
our teeth will not get enough work to keep them in good 










go PHYSIOLOGY, HYGIENE, AND SANITATION 


condition. They need some tough, hard food, like crusty 
bread and hard toast or crackers, to make them chew and 
get exercise. Work makes them strong. 

Teeth need to be kept clean. — When we eat, particles 
of food collect between the teeth and may stay there a 
long time. Starchy food, such as bread and crackers, is 
especially likely to lodge between the teeth and at the 
margin of the gums. This will in time ferment and form 
lactic acid, which attacks the enamel of the teeth and 
causes the formation of cavities. The food left between 
and around the teeth after eating should be removed 
either by rinsing the mouth with water or by brushing 
the teeth with a toothbrush. The teeth are best kept 
clean by brushing with a toothbrush after each meal. It 
is a good plan to brush them also just before going to bed, 
so that the teeth will be clean during the night. 

The use of the toothbrush. — The toothbrush should 
not have too hard bristles or they may injure the gums. 
The brush should be rather soft. In using it the brush 
should be placed on the gums of the upper teeth and then 
moved downward so that the teeth are brushed down¬ 
ward. For the lower teeth the brush should be placed on 
the gums below the teeth and then moved upward so that 
the teeth are brushed upward. In this way the gums are 
not brushed away from the teeth. If we just push the 
brush backward and forward on the teeth, we are likely 
to loosen the gums from the teeth and push them back so 
that more of the teeth is exposed than should be. The 
gums are very important to the teeth and should cling 
closely to them. Anything that pushes the gums away 
from the teeth is bad for them. The inner sides of the teeth 
should be cleaned just as carefully as the outer sides. It 


THE TEETH AND THEIR CARE 91 

is a little more difficult, but it is necessary to keep them 
clean. 

The toothbrush may be used with plain water, or a 
little mild soap may be used with it to clean the teeth, or 
tooth paste may be used. After brushing the teeth it is a 
good plan to rinse the mouth with plain water. The brush 
itself should be kept clean when not in use. 

Proper use of the teeth. — The teeth are intended for 
chewing food. They should not be used to bite thread or 
crack nuts. The enamel is likely to get cracked and broken 



Which Do You Prefer? 


It pays to take care of one’s teeth. Good sound white teeth 
look so much better. Then, too, one can chew one’s food so 
much better with sound teeth. 

if we do, and when the enamel gets broken the teeth are 
more likely to develop cavities. The teeth should be used 
properly and with care. They should not be used for 
purposes for which they are not intended. 

Repair of the teeth. — When a tooth becomes broken 
or develops a cavity, it should be repaired at once before 
further damage is done. It is usually necessary to have a 
dentist repair it. If we do this, we will keep our teeth and 
they will remain useful as long as we live. When a tooth 
aches it usually means there is a cavity in it that needs 










92 PHYSIOLOGY, HYGIENE, AND SANITATION 


attention. It is a good plan for growing boys and girls to 
have their teeth examined by a dentist once or twice a 
year, even if they do not ache. If this is done, small 
cavities will often be found which can be easily filled, but 
which if not found would develop into large holes before 
one would know they were there. A small cavity is much 
easier to fill than a large one, and does not hurt nearly so 
much. 

The best way to have strong healthy teeth is to have a 
strong healthy body properly nourished by the right kind 
of food. If we also give them proper use and exercise, 
keep them clean, and have any small holes that develop 
repaired at once, we will be sure of having good teeth 
with which to chew our food. And besides good bright 
white teeth look so much better than discolored or broken 
ones. Good teeth make us look better and feel better. 

Questions 

1. Of what use are our teeth? 

2. How many sets of teeth does a person have? 

3. What can you say about the first set of teeth? How many 
are there in the first set? 

4. At what age do the second or permanent teeth begin to ap¬ 
pear? How many of them are there when they have all grown out? 

5. How do the teeth resemble bone? 

6. What are the crowns of the teeth? What are the roots? 
What is the pulp? What is the enamel? 

7. Where are the blood vessels and nerves of the teeth? What 
do the blood vessels do for the teeth? 

8. When a tooth aches what is it the tooth’s nerve is telling us? 

9. Does having a healthy body help one to have good teeth? 

10. How does the food one eats affect the teeth? 

11. Do one’s teeth need exercise? Why? How do the teeth get 
exercise? 


THE TEETH AND THEIR CARE 93 

12. Why do the teeth need to be kept clean? What is the best 
way to keep them clean? 

13. How often should the teeth be brushed? How should the 
teeth be brushed? Why should one be careful not to loosen the 
gums from the teeth? 

14. Why should one be careful not to break one’s teeth? What 
can you say about biting thread or cracking nuts with the teeth? 

15. What should be done when a tooth gets broken or has a hole 
develop in it? Why? 

16. Why is it a good plan to have one’s teeth examined by a 
dentist once or twice a year? 

17. Why do we want our teeth to remain in good condition as 
long as we live? 


CHAPTER XVIII 


The Eyes and Their Care 

Our eyes are very important parts of our body. With 
them we see the world about us, we see the trees, the 
flowers, the smiles of our friends, and all the many beauti¬ 
ful things with which we are surrounded. The eyes are 
the windows of the body through which we look out. 
With good healthy eyes we see things clearly as they are. 
If the eyes are injured in any way, we may not see so well 
or so clearly. 

We see things only when there is light. We do not see 
in the dark. The eye is much like a camera. Light re¬ 
flected from whatever object we are looking at enters the 
eye and strikes the back part of the eye, called the retina . 
Then we see the object. It is the light which enters the 
eye that causes us to see. The light enters through that 
part of the eye called the pupil. You will notice that if 
you look at a bright light the pupils of your eye contract 
and become small. This is to shut out as much of the light 
as possible, for bright light shining directly into the eyes 
is harmful. In a dim light the pupils get large so that 
more light will enter the eyes and we can see. In this 
way the eyes can protect themselves to some degree from 
too strong light and help us to see in dim light. But in 
spite of this, if the light is very bright it may injure the 
eyes, and if we try to read or look at small objects in a 
dim light we may hurt our eyes. The eyes therefore need 

94 


THE EYES AND THEIR CARE 


95 


to be protected from too strong light, and should not be 
used for reading or fine work when there is not enough 
light to see well. 

Reading and studying. — In reading and studying we 
should not face a window or a bright light. The window 
or light should be behind us. It is best and most con¬ 
venient for a right-handed person to have the light come 
over the left shoulder and illum¬ 
inate the book he is reading or 
his work. For this reason the 
principal windows in a school 
room are at the back. For this 
reason, too, the blackboard is 
put where the pupils when they 
are looking at it will not have 
the light from a window shining 
in their eyes. 

One should read only when 

standing or sitting, and the book 

or work should be SO placed Our Eyes Are the Windows 

that it can be seen easily and 0F 0uR Bodies 

comfortably. Usually the thing Through them we look out 

and see the world about us. 

we are reading should be held 

about fourteen inches, that is, a little more than a foot, 
away from the eyes. If we attempt to read while lying 
down, the light from the book enters the eye in an 
unnatural direction and reaches the retina at a place 
not usually used. The result is the eyes are easily tired 
and strained, and they may be harmed if much reading 
is done in this way. If one attempts to read on a street 
car or railroad train, he will find it tires the eyes. The 
reason is that on the street car or train there is jarring and 






96 PHYSIOLOGY, HYGIENE, AND SANITATION 


vibration, and the book or whatever one is trying to read 
is constantly shaking. In order to read under such con¬ 
ditions, the eyes have to keep following the slightly shaking 
page. They find this hard work, and as a result soon get 
tired. If we want to keep our eyes in good condition we 
should not read while lying down or while on a moving 
street car or railroad train. 

The eyes, like our other organs, work best when the 
whole body is healthy and strong. When the body is 
sick, the eyes tire more easily than when it is in health. 
When ill therefore we should be especially careful not to 
overwork them. It is also true that the eyes can work 
better when the body is rested than they can when it is 
tired. They work better in the morning when the body is 
rested by a good night’s sleep than they do at night when 
the body is weary. 

Books with fine print are harder on the eyes than those 
with larger print. Shiny paper is harder on the eyes than 
paper that is not shiny. The books easiest on the eyes 
are those with good-sized print on white paper without 
any shine. In reading or doing fine work it is a good plan 
to look up and away from the book or work every little 
while. This rests the eyes. 

Not all eyes see well. — We have learned the eye is like 
a camera. Those who have used a camera know that it 
has many parts and that if the parts are not arranged 
just right, and particularly if the camera is not focused 
properly, it will not take clear pictures. Unfortunately 
some people are born with eyes that do not focus properly, 
and as a result they do not see clearly, or at best see with 
some difficulty. Some people who are born with eyes that 
are good cameras injure them by improper use so that 


THE EYES AND THEIR CARE 


97 


they cannot focus well. Such eyes may see near things 
well but not objects far away, or they may see far objects 
but not small things close at hand. Those who see far 
objects best are said to be far sighted and those who see 
near objects best near sighted. 

Eyes that do not focus well can be helped greatly by the 
use of properly fitted glasses. Any boy or girl who does 
not see well when he reads a book, or who has to bring 
the book close to his face to see the print, or who cannot 
easily see writing on the blackboard should have his eyes 
examined to find out what is the matter. 

Sometimes people seem to see all right but they have 
headaches whenever they use their eyes to read or study. 
This is because their eyes focus with difficulty, and a little 
work tires them. If these people get the right kind of 
glasses, the glasses help the eyes to focus easily, and then 
they can use their eyes without tiring them and without 
getting a headache. 

We can have but one pair of eyes. — We can have but 
one pair of eyes. Those we have must do us all our lives. 
If they are injured in any way by accident or improper use, 
we cannot get new ones. Our eyes are so important to us, 
being the windows through which we look and see the world 
about us, and being able to see well adds so much to our 
usefulness and our pleasures, that it is important to keep 
our eyes in just as good condition as we can. 

Questions 

1. What do our eyes do for us? 

2. Can you tell how we are able to see things? 

3. Why can one not see in the dark? 

4. What do the pupils of the eyes do when a bright light shines 
into them? What do the pupils do when the light is dim? 


98 PHYSIOLOGY, HYGIENE, AND SANITATION 


5. In what kind of light can the eyes see best? 

6. From what direction should the light come when one is 
reading or studying? Can you tell why? 

7. How far from one’s eyes should a book be held when reading? 

8. What can you say about reading while lying down? 

9. Why does reading on a train or street car tire one’s eyes? 

10. What kind of print is easiest to read? What kind of paper 
should be used in books? 

11. How can one rest one’s eyes while reading or working? 

12. Why do some people need to wear glasses? 

13. Why should one be careful and not injure one’s eyes? 

14. If one’s eyes get tired and ache after one has been reading 
or studying what is usually the matter? What should be done? 




CHAPTER XIX 

Why We Wear Clothes and the Kind We Need 

The body needs protection from the sun in summer and 
from the rain and cold in winter. For this purpose we 
wear clothes. In summer when the weather is warm and 
the sun hot, the clothes need to be of a kind that will pro¬ 
tect the body from the sun but will let the body-heat 
escape. Light colored clothes protect the body best from 
the sun, because they reflect the sun’s rays, while black 
clothing absorbs them. For this reason white clothing is 
cooler than dark or black. Linen and cotton clothing let 
heat pass through them better than does woolen. The 
coolest and most comfortable clothing in warm weather is 
therefore light-colored or white cotton or linen garments. 

In winter we need clothing that will keep the body-heat 
from passing away from the body. Woolen garments do 
this best because they are poor conductors of heat, and 
the body heat is held in by them and cannot escape. 
Several thin garments protect the body from cold better 
than one thick one because under each garment there is a 
layer of air, and air confined in this way between the 
clothing is also a poor conductor of heat and serves to 
prevent the escape of the body’s warmth. 

The clothing worn next the skin absorbs the perspiration 
given off by the sweat glands. In this way, especially in 
warm weather, it becomes filled with sweat and the waste 
products in the sweat. For this reason our undergarments 


99 


ioo PHYSIOLOGY, HYGIENE, AND SANITATION 

need frequent changing. In summer they need changing 
and washing more often than in winter. All our garments 
in time become soiled by use and by the perspiration 
which the body is constantly giving off and need washing 
or at least cleaning and airing. The body can be kept 
clean only when the clothing is also clean. Garments 
taken off at night should be so hung up that 
they will air while we are sleeping. 

Our clothing should be so shaped that it 
will not interfere with the movements of the 
body and the action of our muscles. It should 
be so made that the legs and arms can be freely 
used in work and play. It should be loose 
enough so that it does not compress the body. 

Shoes. — Shoes are worn to protect the 
feet from injury as we walk and run in our 
The Shape play and work. Shoes should fit the feet 
of the Nat- comfortably. If they are too narrow or too 

URAL FOOT . . . . . ... 

short or not the right shape, they will press 
the bones of the feet, and especially the bones of the toes, 
into unnatural positions. Improperly shaped shoes not 
only hurt and cause corns and bunions to develop, but 
in time they will actually deform and cripple the feet. 

The natural-shaped foot is shown in the adjoining pic¬ 
ture. The extent to which the feet may be deformed by 
incorrectly shaped shoes is also shown. If an X-ray 
picture is taken of the deformed foot, we find that 
the bones of the toes are bent into unnatural positions. 
This is shown in the picture on page ioi. 

To be comfortable, shoes must not be too narrow or 
too short. When one stands with his weight on his feet, 
they flatten out and become larger and broader. In try- 






OUR CLOTHING 


IOI 


mg on new shoes one should always stand with all the 
weight on one foot so as to see whether the shoe is long 
and broad enough. The shoe should be at least half an 


inch longer than the foot, 
for the big toe always pushes 
forward in walking and run¬ 
ning. In trying on new 
shoes both the right and left 
shoe should be tried on, be¬ 
cause sometimes both shoes 
are not just alike, and some¬ 
times one foot is larger than 
the other. 

The natural foot is much 
more useful and looks better 
than a foot deformed by 
badly shaped shoes. The 
natural foot is stronger and 
running. 



One cannot walk or run well on 
feet crippled in this way. 

is better for walking and 


Questions 

1. Why do people wear clothes? 

2. How do clothes protect our bodies from the sun? 

3. What color of clothes protects us best from the sun? 

4. What kind of clothing is coolest in warm weather? Why? 

5. What kind of clothing keeps the body warmest in winter? 
Why? 

6. Why do several layers of thin clothing keep the body warmer 
than one thick garment? 

7. Why does the clothing worn next the skin need frequent 
changing, especially in warm weather? 

8. Why should clothing not be tight or so made that it inter¬ 
feres with the use of the arms and legs? 


102 PHYSIOLOGY, HYGIENE, AND SANITATION 


9. Why do people wear shoes? 

10. What happens to one’s feet if one wears shoes which are too 
tight or are not the proper shape? 

11. In trying on new shoes why should one always stand up and 
walk about with them on? Why should one try on both shoes? 
How much longer than the foot should the shoe be? Why? 

12. Why is it important not to cripple one’s feet with improperly 
fitting shoes? 


CHAPTER XX 


Microbes, Good and Bad 

All about us we find plant and animal life. The trees 
and shrubs and vegetables we recognize as plants. Among 
the animal life we know are domestic and wild animals, 
fish, and insects. All of these we have seen. 

We have learned that the human body is made up of 
little cells. Plants and animals are also made up of cells. 
The plants are made up of plant cells and the animals of 
animal cells. The bodies of the animals and plants we see 
are made up each of many thousands or millions of cells. 
But there are plants so small they are made up of a single 
plant cell, and there are forms of animal life so small that 
they consist of a single animal cell. These minute living 
things are so small they can be seen only by the use of a 
powerful microscope, and we call them microbes. Some¬ 
times they are spoken of as germs. 

The plant and animal microbes are very much alike, 
and it is often difficult to tell whether a microbe is an ani¬ 
mal or a plant. It was only after man had learned how to 
make powerful microscopes that it was discovered there 
are such things as microbes. The first microbes were seen 
by the use of a microscope about the year 1700. We now 
know the living things in the world are not only the plants 
and animals we see about us, but also the microbes we 
cannot see except by the use of a microscope. 

Where microbes come from. — It was at first thought 

103 


104 PHYSIOLOGY, HYGIENE, AND SANITATION 


by many that these minute living bodies which were 
found in dirty water, milk, and decaying things must 
develop from the substances in which they were found. 
These people thought that when meat decayed it formed 
microbes. It was soon found, however, that decaying 
things did not form microbes, but that all microbes came 
from other microbes. It was found that, if all the microbes 


cf Pu 


itr^ 








€/i 










3 




Different Kinds of Microbes 
As they would appear through a powerful microscope. 


on meat were killed and no more allowed to get on it, the 
meat would not spoil and decompose, and that if all the 
microbes in milk were killed and no others allowed to get 
into it, the milk would not sour. Then people knew that 
it was the microbes that made the meat rot and the milk 
turn sour. 

It was also found that there were many different kinds 
of microbes and that each kind grew only from others of 











MICROBES, GOOD AND BAD 


105 


the same kind, just as oak trees always come from acorns 
which have grown on other oak trees, as walnut trees 
always grow from walnuts which have grown on other 
walnut trees, as wheat grows from wheat, barley from 
barley, and chickens from the eggs of other chickens and 
robins from the eggs of other robins. 

How microbes grow and multiply. — If microbes live in 
milk, they get their food from the milk. A microbe grows 
to full size, then usually divides into two parts. Each 
part then consumes food, grows to full size, and divides 



Showing how Microbes multiply 

Each microbe as shown here is dividing into two. Each of these will 
then grow to full size and again divide into two. 


into two. Each of these grows and divides. In this way 
under favorable conditions a microbe may grow to full 
size and divide into two in fifteen or twenty minutes, and in 
another fifteen or twenty minutes each of these two will 
have divided into two, thus making four. In another twenty 
minutes there will be eight and in another sixteen. In 
this way one microbe may become many millions in a day. 

Some of the microbes live in the earth, some in water, 
some on plants, some on animals, and some only in ani¬ 
mals. Many are useful and may be said to be “good 
microbes.” Others do injury to plants or animals or man 
and are “bad microbes.” 













io6 PHYSIOLOGY, HYGIENE, AND SANITATION 


Good microbes. — Many microbes live in the earth and 
by their presence make it possible for plants to grow. If 
it were not for the presence of these in the soil, we could 
not grow our farm products, wheat, oats and hay, or our 
vegetables and fruits. Farming would be a failure if it 
were not for the help of these good microbes. 

The yeast used in mak¬ 
ing bread is filled with a 
certain kind of good mi¬ 
crobe which grows and in 
growing gives off a gas 
which fills the dough with 
bubbles and causes it to rise. 
When the bread is baked, 
the yeast microbes are 
killed, but they have done 
their work and made the 
bread light and full of holes. 
The pleasant taste of 
butter is due to the action of microbes which were in the 
milk from which the butter was made. The bad taste of 
some butter is caused by other microbes which have got 
into it. The flavor of different kinds of cheese is due 
to certain microbes used in making them. Vinegar is 
made from apple juice, but it is certain microbes that 
do it by forming acid in the apple juice. Thus they give 
us our vinegar. 

If, when an animal dies, its body is left in the woods, 
it soon begins to decay or decompose. In time it disap¬ 
pears, and there is left only the hard, chalky bones. It is 
certain good microbes that decompose these dead animal 
bodies. Were it not for them, dead bodies would not 







Yeast Microbes 
As seen through a microscope. 







MICROBES, GOOD AND BAD 107 

decompose, but the woods and fields would be filled with 
them. 

The same thing happens to plants and trees that die. 
They rot and disappear. It is good microbes that cause 
them to rot. If it were not for this, the woods and fields 
would be so covered with dead plants and trees that there 
would not be room for others to grow. 

When microbes decompose dead bodies and dead plants 
they change them into substances which go back into the 
earth and enrich the soil. A tree grows and in growing 
takes from the soil its food, plant food. This food taken 



Microbes of Typhoid Fever Microbes of Diphtheria 
They are magnified about 1000 times larger than their real size. 


from the soil makes the tree. The tree finally becomes old 
and of little use and dies. Then the microbes get to work 
and cause it to rot, and in this way the substances and 
food which the tree in growing took from the earth are 
returned to the earth and can be used again by other trees 
and plants. 

Bad microbes. — But there are some microbes that live 
on living plants and animals and do them harm. Some¬ 
times they live on the surface of the plant or the skin of • 
the animal, and sometimes they penetrate deep into the 
plant or into the blood and tissues of the animal. When 
a living plant or animal is affected in this way by microbes 
which do it harm, we say it is diseased. The microbes 


io8 PHYSIOLOGY, HYGIENE, AND SANITATION 


which cause diseases in plants are usually different from 
those causing diseases in animals. Some microbes will 
attack only one kind of plant and some only one kind of 
animal. Mildew and black spot on plants, distemper in 
animals, and measles and diphtheria in man are caused 
by bad microbes. Each disease is always caused by the 
same microbe. One microbe always causes mildew in 
plants. Another kind of microbe always causes measles 
in man, and still another kind always causes diphtheria. 

Some microbes are among man’s best friends, others 
are his worst enemies. Some help him grow his food. 
Some help him make bread, and cheese, and vinegar, but 
others he must fight and destroy wherever he meets them 
or they will destroy him. 


Questions 

1. What can you say about how the body is made up of cells? 
How small are these body cells? How many of them are there? 

2. Are plants also made up of cells? 

3. How many cells are there in the smallest plants? How many 
in the smallest forms of animal life? How can we see these smallest 
plants and smallest forms of animal life? What are they called? 

4. What do oak trees grow from? What does wheat grow from? 
What do chickens grow from? What do robins grow from? What 
do microbes grow from? 

5. How do microbes multiply? How many microbes may de¬ 
velop in a day from one microbe? 

6. Where do microbes live? If a microbe lives in milk where 
does it get its food? If it lives on meat where does it get its food? 

. If it lives in one’s mouth where does it get its food? If it lives in 
one’s lungs where would it get its food? Do all plants and animals 
have to have food? Why? 

7. What can you say about how certain good microbes help the 
farmer? How do certain microbes help in making bread? In mak¬ 
ing butter? In making cheese? In making vinegar? 


MICROBES, GOOD AND BAD 109 

8. What do some microbes do to dead animals and plants? 
Why are these good microbes? 

9. How do some microbes injure living plants and animals? 
What do we say of a living plant or animal which is being injured 
by microbes in this way? 

10. Name a disease of pla,nts caused by microbes. Name a 
disease of animals. Name a disease of man caused by them. 


CHAPTER XXI 


What Disease is and What it Means 

When all the organs and tissues of one’s body machine 
are working properly and as they should, one is healthy. 
But when one’s organs or tissues have become injured so 
that they cannot do their work well, or when the body 
does not get the food it needs, or enough rest, or when one 
has taken into the body poisons that injure the organs or 
tissues, or when microbes get into the body and grow there 
and do injury to the organs and tissues, one is not well 
but is sick. Then we say the person has a disease. When 
the body machine is unable to do its work properly, we 
say it is diseased. 

Diseases due to injury of organs. — Some diseases are 
due to improper use of parts of the body. One may over¬ 
exert himself in a foot race and make the heart work 
harder than it can stand and in this way injure it so that 
for some time, perhaps for years, it will not be able to do 
its work well. Or one may eat food that the stomach 
cannot digest. If this is done often, the stomach may 
become so injured that it will not digest good food as it 
should. Or one may read much in a dim light, or with 
the sun shining on the book, or while lying down, and 
thus so injure the eyes that they will not work well. One 
may break his teeth by cracking nuts with them and have 
holes develop which unless cared for by a dentist will 
destroy the teeth. One may wear shoes that fit the feet 


no 


DISEASE AND WHAT IT MEANS 


hi 


so poorly that the bones of the feet are forced out of place 
and one becomes crippled. All these things we can avoid 
by the proper use of our body machines. 

Disease due to not giving the body the food it needs. — 
In a previous chapter we learned about the various kinds 
of food the body must have to supply proper nourishment 
to all the organs and tissues. We learned that proper 
food is especially important to the growing boy and girl. 
Young animals and boys and girls will not grow as they 
should unless they eat the kinds of food the body needs. 
The body cannot grow unless it is furnished the materials 
and substances out of which it can build tissue and make 
the body larger. To build a house you need lumber, 
bricks, mortar, laths, nails, shingles, window glass, putty, 
and paint. Likewise to build a body many materials are 
needed, and these we must get in our food. If one does 
not eat the materials the body needs, he not only will not 
grow, but he will not be well. He will not have the 
strength and energy he should have. One may eat a lot 
of food but unless it consists of the kinds the body needs 
he will not be well. He may even get very sick. 

There are four diseases which make people very sick and 
are known to be caused by not eating the foods the body 
needs. These diseases are called scurvy, rickets, pellagra, 
and beriberi. You do not need to remember their names 
but should remember that one may become very sick un¬ 
less he feeds his body the foods it needs. 

Disease due to not getting enough rest. — If one does 
not get enough sleep, the body cells do not have an oppor¬ 
tunity to become rested and restored after the day’s work. 
If day after day one does not get enough sleep, the body 
cells get so that they are tired and fatigued all the time, 


112 PHYSIOLOGY, HYGIENE, AND SANITATION 


and in this condition they cannot do their work well. 
The brain suffers most, but all the organs do their work 
less well. Without sufficient sleep young animals, and also 
boys and girls, will not increase in weight as they should nor 
will their growth be as rapid as it ought to be. They may 
even lose in weight. People, young and old, who do not get 
enough sleep feel tired and are less cheerful and happy. 
They often become irritable and cross. And all because their 
body cells are tired and because they get too little sleep. 

Disease due to poisons taken into the body. — Poisons 
are substances which when taken into the body injure the 
body cells. Some poisons, like carbolic acid, kill the cells 
whenever they touch them. Others, like phosphorus, may 
kill some of the body cells but they act more slowly. 
Others, like nicotin and alcohol, do not kill the cells but 
make them sick so that they do not work well. Many 
substances used as medicine are poisons if taken into the 
body in too large doses. The effect of a poison usually 
depends on the amount taken. 

Nicotin is the poison contained in tobacco. People get 
it into their bodies when they chew or smoke tobacco, 
also when they use snuff, for snuff is powdered tobacco. 
Nicotin is a very powerful poison. Even in smoking one 
may get enough of it to make him very sick. It is espe¬ 
cially injurious to young people. 

Alcohol is another poison which does great injury to the 
body cells. It injures practically all the organs and tissues 
of the body. Even small amounts do some injury. 

Tea and coffee contain a substance called cajfein. It is 
used sometimes in small doses as a medicine. It has the 
effect of making one wakeful so that one will not get as 
much sleep as he needs. It also makes the heart work 


DISEASE AND WHAT IT MEANS 


II3 

faster. The result is that a person who drinks tea and 
coffee may not get enough rest and the heart may be over¬ 
worked and he may become cross and irritable. Caffein, 
like many other poisons, is especially injurious to young 
animals. Tea and coffee therefore should not be drunk 
by growing boys and girls who want to keep themselves 
in good health. 

Disease due to microbes. — It has been explained in a 
previous chapter that some microbes would grow in the 
body. Microbes to live and grow and multiply must have 
food, just as plants and animals do. Those that live in 
one’s body must find their food there. Some microbes 
live in our mouths, where they find what they need to eat 
in the little scraps of food left around the teeth after 
meals. Some of these may injure the teeth, while some of 
them seem to do no harm. The cleaner we keep our 
mouths and teeth, the fewer of them there will be. 

There are seldom many microbes in the stomach, be¬ 
cause any that get there are usually killed by the acid in 
the gastric juice. The intestine contains many microbes. 
These find what they need to eat in our food as it passes 
through the intestine. Ordinarily the microbes in the in¬ 
testine do no harm, although sometimes kinds get there 
which ferment the food and form gas or poisons which 
may do harm. 

Other microbes when they get into the body live only in 
the blood and tissues, where the only food they can get is 
the blood itself and the body cells. If these microbes 
grow and multiply, as they sometimes do, so that there are 
a great many of them, they will do serious injury to the 
blood and body cells. 

Microbes not only consume food, but they also give off 


114 PHYSIOLOGY, HYGIENE, AND SANITATION 


waste products and other substances, as do plants and 
animals. Most of the microbes which can live in the blood 
and tissues give off poisons; some of them give off power¬ 
ful poisons. These poisons may make us very sick. One 
microbe of this kind that lives in the blood and tissues and 
gives off a powerful poison causes the disease we call 
typhoid fever. When this microbe gets into the body it 
grows and multiplies so that there may be millions of them. 
As they grow they give off a poison which makes a person 
sick. Another microbe which gets into the body and 
grows and gives off a poison produces a sickness we call 
measles. Another causes scarlet fever, and another small¬ 
pox. There are a great many diseases caused in this way. 
Each disease is caused by a special microbe and the same 
microbe always produces the same disease. 

How the body fights the microbes. — When disease mi¬ 
crobes get into the body, the body cells begin to fight 
them. First the white blood corpuscles or cells, called 
phagocytes, attack the microbes and attempt to devour 
them. They may be able to kill all the microbes, and if 
they do one does not get sick. But there may be too many 
of the microbes, or they may multiply so rapidly that the 
phagocyte cells can devour only a small part of them. 
Then the body cells begin making substances which will 
kill the microbes and other substances which will destroy 
their poisons. But it takes the body cells some time to do 
this, and before enough of the substances can be made the 
microbes may multiply to many millions, and their poison 
may make the body very sick. 

When a person has fever and aches and gets weak, these 
things are caused by the poisons given off by the microbes. 
At this time the poisons are injuring the body cells, and 


DISEASE AND WHAT IT MEANS 


ii5 

the body has not yet had time to form the substances 
which will kill the microbes and destroy their poisons. 

When the sick person begins to feel better, it means 
that the body cells have formed these substances and the 
microbes are being rapidly killed and the poisons are either 
being destroyed or excreted from the body. It is fortunate 
the body has the power to form these substances, for if it 
did not, we should not get well when we had such diseases 
as measles, scarlet fever, and diphtheria. The microbes 
would destroy our bodies whenever we got these diseases. 

When the body has formed these substances which kill 
the microbes, and the microbes have been killed, and the 
body recovers from the sickness, the substances still re¬ 
main in the body, and as long as they do a person will not 
get the same disease again. This is because if any of the 
microbes should get into the body they would be killed 
at once by the protective substances there. 

After some diseases these substances remain in the body 
a long time, sometimes as long as the person lives. This 
is true usually after measles, scarlet fever, and smallpox, 
and explains why when we have once had one of these 
diseases we seldom have it again. 

After some diseases these substances remain in the body 
only a short time. This is true in the diseases we call “colds” 
and explains why we may have a cold every few weeks. 

The substance which the body forms to kill the microbe 
of measles is different from the substance it forms to kill 
the microbe of scarlet fever. The substance formed is 
different for each kind of microbe. The substance which 
kills the measles microbe will not kill the scarlet fever or 
diphtheria microbe. An attack of measles therefore will 
keep our bodies from again having measles, but will not 


n6 PHYSIOLOGY, HYGIENE, AND SANITATION 


protect them from other diseases, and an attack of scarlet 
fever will keep the body from again having scarlet fever 
but does not protect it from measles. 

Questions 

1. What is a healthy body? 

2. What is meant by a diseased body? 

3. How may the body machine become diseased by the improper 
use of parts of the body? How may the heart become diseased? 
The stomach? The eyes? The teeth? The feet? 

4. What will happen to the body machine if one does not eat 
the foods the body needs? Why? 

5. What will happen to the body machine if one does not get 
enough sleep? Why? 

6. What are poisons? Name some. 

7. What do poisons do to the body cells? 

8. How do some microbes injure the body? Where do these 
microbes get their food? What can you say about the poisons they 
form? Name two diseases caused by microbes. Is typhoid fever 
always caused by the same microbe? Is the microbe which causes 
measles different from the one which causes typhoid fever? Is the 
one causing smallpox still a different one? 

9. When disease microbes get into the body, what do the body 
cells do? What do the white corpuscles do? If the microbes con¬ 
tinue to grow what do the body cells do? 

10. When a person has a microbe disease, what is happening 
when he has fever and aches and feels sick? What does it mean 
when he begins to feel better? 

11. What would happen when one got a microbe disease, if the 
body cells did not form the substances which destroy the microbes 
and their poisons? 

12. When one has once had measles, scarlet fever or smallpox 
why does one seldom have the disease again? 

13. Why can one have some diseases many times? 

14. Do the substances which the body cells form to kill the mi¬ 
crobes and destroy the poisons of one disease protect the body from 
other diseases? 


CHAPTER XXII 


Why Some Diseases Spread from One Person to Another 

Many diseases spread from one person to another. 
Diseases which do this we say are “ catching.” All diseases 
which can spread from one person to another are caused 
by microbes. It is the microbes that are spread from the 
sick to the well. 

How microbes leave the bodies of the sick. — In some 
diseases the microbes are not only in the blood and tissues, 
but there are many of them in the mouth, throat, and 
nose. This is true in measles and scarlet fever. In these 
diseases, when the sick person coughs or sneezes the mi¬ 
crobes are scattered about and may get on anyone who is 
near at the time. Many of the microbes will be on the 
handkerchief used by the sick person. If others touch the 
handkerchief, they will get the microbes on their hands, 
and if they do not wash their hands carefully they may 
get the microbes into their mouths when they eat. If 
they are about the sick person when he coughs or sneezes, 
they may breathe in the microbes scattered by the cough¬ 
ing and sneezing. 

Also, when the sick person drinks out of cups or glasses, 
and uses spoons and forks in eating, the microbes from the 
mouth get on the cups, glasses, spoons, and forks. If the 
microbes on these are not killed by putting them in boiling 
water, anyone who uses them may get the living microbes 
in his mouth, and then he may develop the disease. Even 


n8 PHYSIOLOGY, HYGIENE, AND SANITATION 


when a person talks, he scatters about him microbes from 
his mouth. If the person has measles or scarlet fever, he 
will scatter the disease germs. 

In diphtheria and also in common colds the microbes 
are in the mouth in large numbers and are scattered in the 
same way. Anything that the sick person puts in his 
mouth will get disease microbes on it. Cups, glasses, 
spoons, forks, chewing gum, toys, lead pencils, whistles, — 



Two Kinds of Mosquitoes 

The mosquito on the left spreads malaria; the one on the right is 
harmless. Notice the different ways in which they stand. 


all will be covered with microbes if put into the mouth of 
a person with one of these diseases. 

In other diseases the microbes are not only in the blood 
and tissues, but also in the intestine. This is true in 
typhoid fever and cholera. In these diseases the microbes 
are contained in the bowel movements and leave the sick 
in this way. Anyone who gets typhoid fever gets it be¬ 
cause he has got into his mouth microbes which have 
come from the body of some one else who had typhoid 
fever. This may happen in several ways. Flies in search 
of food may get at the bowel movement and get the 
microbes on their feet, then they may fly to another house 











WHY SOME DISEASES SPREAD 


119 

where people are eating and walk over the bread or other 
food, and wherever they walk they will leave the microbes 
of typhoid fever, and those who eat the food may get the 

microbes into their mouths and become sick with the dis- 

% 

ease. 

Or the bowel movements may be thrown out on the 
ground and the rain may wash the microbes into a well. 
Then those who drink the water 
from the well may get the dis¬ 
ease. These microbes often get 
into water, and sometimes into 
milk. This is why people should 
be so careful of the water they 
drink, and why city health de¬ 
partments watch so carefully the 
milk that is sold. 

The microbes of some diseases 
are only in the blood of the sick 
person. Malaria and yellow fever 
are diseases of this kind. In these two diseases the mi¬ 
crobes are spread from the bodies of the sick to the bodies 
of the well by mosquitoes. The mosquitoes bite and suck 
blood from a person sick with one of these diseases, and 
then later bite well persons and in biting them inject the 
disease microbes into their bodies. In this way these dis¬ 
eases spread. If there are no mosquitoes, these diseases 
will not spread. 

Whenever anyone gets sick with a disease caused by 
microbes, it is because he has gotten into his body microbes 
which have come from the body of someone who had the 
disease. Some of the microbe diseases are common colds, 
mumps, measles, whooping cough, scarlet fever, diphtheria, 



The Mosquito that 
Spreads Yellow Fever 




120 PHYSIOLOGY, HYGIENE, AND SANITATION 


chickenpox, tuberculosis, influenza, infantile paralysis, 
smallpox, malaria, cholera, yellow fever, and typhoid fever. 
There are many others. All diseases which are spread 
from one person to another are due to microbes. 


Questions 

1. When a disease is spread from one person to another, what 
is it which causes it to spread? What is it which is really spread 
from the one person to the other? 

2. How are microbes spread from sick people to others when 
the disease microbes are in the sick person’s mouth? How by cough¬ 
ing and sneezing? How by handkerchiefs? How by cups, glasses, 
spoons and forks? 

3. Name a disease in which the microbes are in the sick person’s 
mouth. 

4. Name a disease in which the microbes are in the sick person’s 
intestines. How may the microbes of this disease be spread from 
the sick person to others? 

5. Name a disease in which the disease microbes are only in the 
sick person’s blood. 

6. How are malaria and yellow fever spread? 

7. How do mosquitoes spread malaria and yellow fever from 
one person to another? 

8. Will malaria spread from one person to another if there are 
no mosquitoes? 

9. Name as many diseases as you can which are spread by 
microbes. 

10. When a disease can be spread from one person to another, 
what is it due to? 


CHAPTER XXIII 


What we can do to Protect Ourselves from Diseases 

Caused by Microbes 

Nobody wants to be sick. Everybody wants to keep as 
free from disease as possible. Some diseases so injure the 
body machine that it cannot keep on running. Life then 
leaves the body and the body dies. Other diseases do 
some injury to the body machine but not so much that it 
cannot keep on running. Each sickness and each attack 
of disease by doing some injury to the body shortens the 
time the body machine will be able to run. Each attack 
of disease in this way shortens the time the body will be 
able to live. 

We can do much to keep our bodies from getting disease. 
By using the body properly, by getting enough sleep so it 
can have sufficient rest, by eating the food the body needs, 
by not injuring it with poisons, and by giving it the exer¬ 
cise it needs, we can help the body keep healthy and 
strong. This will even help keep the body free from mi¬ 
crobe diseases, for some microbes cannot get a start in a 
body that is healthy and strong. There are some disease 
microbes however that can cause disease whenever they 
get into the body. The only way we can protect ourselves 
from the diseases caused by these is to keep away from 
the microbes, or at least not let them get into our 
bodies. 

Keep away from the sick. — As people sick with mi- 


122 PHYSIOLOGY, HYGIENE, AND SANITATION 


crobe diseases have the microbes in their bodies and often 
in their mouths and on their handkerchiefs and on the 
bedding and other things about them, anyone going near 
the sick may get the microbes on him and possibly in his 
mouth. The best thing to do is to keep away from persons 
sick with such diseases unless, as sometimes happens, we 
have to be the nurse and take care of them. 

Caring for the sick. —■ If one is taking care of a person 
sick with a microbe disease, his work is not only to wait 
on and care for the sick person, but also to keep the mi¬ 
crobes from getting scattered about on things and from 
getting on other people. If the disease is one in which the 
microbes are in the sick person’s mouth and nose, his 
handkerchiefs should be boiled, and the dishes from which 
he eats should be scalded with boiling water to kill the 
microbes. It is really better to use pieces of cloth instead 
of handkerchiefs. These can be burned. Flies should be 
kept out of the sickroom, as they may crawl on the soiled 
handkerchiefs, get microbes on their feet, and then fly to 
the dining room and walk over the bread and leave the 
microbes there. Whenever the nurse has handled the sick, 
or handkerchiefs or cloths used by the sick, she should 
wash her hands well with soap and water. It is a good 
plan to have a bowl of some disinfecting solution which 
will kill the microbes. The nurse can then dip her hands 
into the solution and be sure that all the microbes which 
were not washed off will be killed. 

If the disease is one in which the microbes are in the 
sick person’s intestine, the microbes in the bowel move¬ 
ments should be killed by putting in chloride of lime or 
carbolic acid, or some other substance which will kill them. 
No flies should be allowed to get into the sick room, or 


HOW TO PROTECT OURSELVES FROM DISEASE 123 

they will soil their feet and carry the microbes to other 
people’s food. 

If the disease is malaria, all the mosquitoes in the room 
should be killed and none allowed to get in from outside. 
No mosquito should be allowed to get to the sick person, 
for if it does it may carry the microbes away and inject 
them into someone else and thus spread the disease. 

Keep flies away from your food. — Flies are unclean 
things. In their search for food they go to 
all sorts of places and walk in all sorts of 
things. They walk in the sputum of the sick, 
they crawl over the pus from running sores, 
they eat from bowel movements wherever they 
find them. Then they often fly to people’s 
houses and walk over the food, and if their 
feet are dirty and have disease microbes on 
them they will leave them on the food. In 
this way many diseases are spread. In this 
manner we may get disease microbes from a 
sick person who lives some distance away and 
whom we have never seen. Flies are nasty 
things and dangerous. By keeping them away 
from our food and out of our houses we 
can help protect ourselves from getting disease mi¬ 
crobes. 

Avoid drinking polluted water. — Microbes which live 
in the intestines frequently get into well water and into 
streams and rivers. In cities the drains from the bath¬ 
rooms and toilets empty into the sewers, and the sewers 
frequently empty into the rivers. The sewage carries with 
it the microbes which come from the intestines of the 
sick as well as of the well. In this way river water fre- 



Foot of a 
House-Fly 

(Magnified) 



124 PHYSIOLOGY, HYGIENE, AND SANITATION 

quently contains disease microbes, and especially the mi¬ 
crobes of typhoid fever. Typhoid fever is often spread in 
this manner. One should drink only water known to be 
free from pollution. Very often cities filter all the water 
supplied to the people. This is to get rid of the disease 
microbes. If one is in doubt as to whether water is safe 
to drink, the water can be boiled. This kills the microbes, 
and it is then safe. 

Drink safe milk. — There are several disease microbes 

which, if they get into 
milk, will grow and mul¬ 
tiply so that a few may 
become millions. This is 
true of the microbes caus¬ 
ing typhoid fever, scarlet 
fever, and diphtheria. 
Often a person engaged 
on a farm in handling 
milk, or perhaps milking 
cows, will be just coming down with one of these diseases, 
or he may be just getting well from an attack. If in 
handling the milk his hands are dirty, or if he sneezes or 
coughs, microbes from his nose or mouth may get into 
the milk, where they will live and perhaps multiply. 
Then those who drink the milk will take the microbes 
into their bodies and many will develop the disease. 

Then, too, cows frequently have tuberculosis, and the 
microbes of this disease often get into the milk. The only 
really safe milk is either boiled milk or pasteurized milk. 
When milk is pasteurized it is heated just hot enough to 
kill the disease germs but not hot enough to make the 
milk taste cooked. Properly pasteurized milk contains no 




A Home Pasteurizing Apparatus 





































HOW TO PROTECT OURSELVES FROM DISEASE 125 


disease germs. Much of the milk sold in cities is now 
pasteurized. 

Keep things out of the mouth. — Things which have 
been in the mouths of other persons have on them some of 
the microbes which have been in their mouths. People 
often stick lead pencils in their mouths. This should not 
be done, especially if others have used them. When others 
have used a cup or glass to drink from, there will be mi¬ 
crobes on it from their mouths. Anyone drinking out of 
the cup or glass will get into his mouth microbes from the 
mouths of those who have used it before him. One should 
therefore not use common drinking cups or glasses used by 
others. 

Protection by vaccination. —• There are several diseases 
against which we can protect ourselves by vaccination. 
The most common of these are smallpox, typhoid fever, 
and diphtheria. We should all be vaccinated against 
smallpox, because it is such a dangerous disease and dis¬ 
figures one so much. In places where there are many 
cases of typhoid fever, vaccination is perhaps the easiest 
and best way to protect ourselves against this disease, too. 

Questions 

1. What does disease do to the body machine? 

2. Does every attack of illness damage the body machine? 

3. When does the body machine stop running? 

4. How do sickness and disease shorten one’s life? 

5. What can one do to keep from getting sick? 

6. How do microbes cause disease? 

7. How are microbe diseases spread? 

8. What, danger is there in going near a person who has a mi¬ 
crobe disease? 

9. Name some of the microbe diseases. 


126 PHYSIOLOGY, HYGIENE, AND SANITATION 

io. If one is taking care of a person sick with a microbe disease 
what should he do besides look after the needs of the sick person? 

n. What precaution should be taken if the disease is one in which 
the disease microbes are in the sick person’s mouth and nose? 

12. What should be done with the handkerchiefs of a person 
sick with a microbe disease? 

13. What would you do with the dishes used by a sick person 
who has a microbe disease? 

14. What can you say about flies in a sickroom? Why are they 
dangerous? 

15. Why should persons taking care of the sick wash their hands 
frequently? 

16. When disease microbes are in the diseased person’s intestines 
as they are in typhoid fever and cholera, what precautions should 
be taken with the bowel movements? 

17. What precautions should be taken in a case of malaria? If 
there are any mosquitoes in the room what should be done? Why 
should all mosquitoes be kept away from the sickroom? 

18. What do flies eat? How do they spread disease? How may 
they contaminate one’s food? 

19. What kind of disease microbes are most likely to get into 
water? 

20. What disease is most often spread hy drinking polluted water? 

21. How may water always be made safe to drink? 

22. Which disease microbes will grow in milk? How do these 
microbes get into milk? 

23. What disease do cows have which people also have? Do the 
microbes of this disease get into the milk? 

24. How may disease microbes in milk be killed? 

25. Why should we not put into our mouths things which have 
been in other people’s mouths? 

26. What can you say of the practice of putting lead pencils in 
one’s mouth? 

27. Why should we not use public drinking cups or drinking 
glasses others have used? 

28. Against what diseases can one be protected by vaccination? 


CHAPTER XXIV 


Some Diseases are Spread by Insects 

Certain diseases are spread by insects. Malaria and 
yellow fever are spread by mosquitoes. The mosquitoes 
bite the sick and suck their blood and with the blood 
suck up the microbes of these diseases. Later they bite 
healthy people and give them the disease. Typhus fever 
is spread by the body louse. The 
lice bite persons with typhus fever, 
then later get on the bodies of well 
persons and in biting them give 
them the disease. Plague is a dis¬ 
ease which affects rats. The fleas on 
the sick rats get the microbes of 
plague in their stomachs when they 
suck the blood of the rats. Later 
they may get on people and in biting 
them give them this disease. House 
flies spread diseases, but they do it 
by getting microbes on their feet 
and legs from sputum and body 
excretions and carrying the microbes 
to the food people eat. 

Malaria. — Malaria is a very common disease in many 
parts of the world. It is one of the diseases which had to 
be controlled before it was possible to build the Panama 
Canal. It was so prevalent in the Canal Zone that most 

127 



Shows Red Blood 
Corpuscles from a 
Person who has Ma¬ 
laria 

The black spots are 
malaria microbes. No¬ 
tice how they are living 
inside the red blood cor¬ 
puscles. 



128 PHYSIOLOGY, HYGIENE, AND SANITATION 


of the workmen would become sick and many of them die. 
It was only by preventing this disease that the work could 
be carried on. The disease was controlled by killing as 
many of the mosquitoes as possible and by keeping those 
that were not killed from biting the men. This was done 
by screening the houses where the men lived so that the 
mosquitoes could not get in. 

Malaria is spread only by the bite of mosquitoes. It 
was at one time a common disease in all parts of the 



Microbes of Malaria 

As seen through a microscope. These get into the blood by the bite of 
a mosquito and live in the red blood corpuscles. 

United States. It is still a common disease in parts of the 
Southern States, and in some sections of California, and in 
certain of the Northern States. 

Malaria in the United States usually does not cause 
people to die, but where it is common it keeps people sick. 
It keeps children sick and away from school. It makes 
men too sick to work. It makes many people just sick 
enough so that while they can do some work, they cannot 
do as much as they would like to do, nor can they do as 
good work as they would if they were well. It not only 
makes people sick, but it makes them live a shorter time 




SOME DISEASES ARE SPREAD BY INSECTS 129 

than they would if they did not have the disease, for like 
the microbes of other diseases, the microbe of malaria 
gives off poisons which injure the organs and tissues of the 
body so that they wear out sooner than they should. 

There are many kinds of mosquitoes just as there are 
many kinds of deer. Some mosquitoes fly and bite mostly 
in the daytime, some 
fly and bite mostly at 
night. Some breed 
and lay their eggs 
mostly in cisterns and 
tubs and barrels of 
water about the 
houses; some lay their 
eggs in swamps and 
ponds. They all lay 
their eggs in water. 

Mosquitoes live only 
near where there is water in which they can lay their eggs. 

Mosquitoes seldom fly more than half a mile from the 
water in which they lay their eggs, and they seldom fly so 
far. A wind may carry them farther, but mosquitoes do 
not like to get caught in a wind and try to keep out of it. 

The mosquito lays its eggs on the surface of the water. 
In a day or two the eggs hatch and out of each egg there 
comes a “wiggle-tail” or “wiggler,” as they are called. 
These live in the water, swimming about in search of food, 
and coming to the surface every minute or two to breathe. 
They breathe air and have to come to the surface to get 
it. After living eight or nine days in the water, or some¬ 
times longer, each “ wiggle-tail ” develops into a mosquito. 
In doing this it comes to the surface and the mosquito flies 



Shows a mass of Mosquito Eggs above 
and Many Wigglers or Wiggle- 
tails below 









130 PHYSIOLOGY, HYGIENE, AND SANITATION 

away. These mosquitoes which develop from the “wiggle- 
tails” will bite people, and lay more eggs, which will make 
more “wiggle-tails,” which will make more mosquitoes, 
and so they keep on until cold weather comes and kills 
most of them and keeps those that are left from laying 
eggs. This is the reason why in places where the winters 
are cold, mosquitoes are troublesome only during the 
summer. In places far south, like the Canal Zone, where 
the weather is warm all the year, the mosquitoes live and 
lay their eggs all during the year. 

Not all kinds of mosquitoes spread malaria. The kind 
which spreads this disease is known as the Anopheline 
mosquito. It flies and bites mostly in the evenings and 
at night. It seldom bites during the daytime. It lays 
its eggs in ponds, swamps, and collections of water in the 
fields and woods. It is seldom found very far from such 
bodies of water. To protect ourselves from malaria we 
must keep these mosquitoes from biting us. 

The best way to protect ourselves from malaria would 
be to kill all the mosquitoes if we could. They could be 
kept from laying their eggs and multiplying, if all the 
ponds and swamps in which they lay their eggs could be 
filled with earth or drained dry. Sometimes this can be 
done. Then the mosquitoes soon disappear. Sometimes 
the pond or swamp cannot be drained, but small fish can 
be put into it which will eat the “wiggle-tails” as fast as 
they hatch from the eggs. This prevents the “wiggle- 
tails” from developing into mosquitoes. Or sometimes 
crude oil or kerosene is spread on the surface of the water. 
This prevents the “wiggle-tails” from being able to get 
air to breathe and kills them. 

But in places where malaria is present people can do 


SOME DISEASES ARE SPREAD BY INSECTS 131 


much to keep from getting the disease by carefully screen¬ 
ing their houses. If houses are well screened the mos¬ 
quitoes which come flying around at night to bite people 
will not be able to get in. 

Where much malaria is present, it is likely to be the 
most serious disease which affects the people. It keeps 
people from being healthy and strong. Every one should 
do all he can to keep from getting it. 


Questions 

1. What insects spread disease? 

2. What diseases are spread by mosquitoes? By body lice? 
By fleas? 

3. How do mosquitoes spread disease? 

4. How do flies spread disease? 

5. How do people get malaria? Is malaria spread in any other 
way? 

6. How was malaria prevented when the Panama Canal was 
built? 

7. Is malaria a serious disease? Why? Does it kill many 
people? Does it shorten their lives? How? 

8. What can you say about the different kinds of mos¬ 
quitoes? 

9. Where do mosquitoes lay their eggs? Do mosquitoes ever 
live far away from water in which they can lay their eggs? How 
far do mosquitoes fly? 

10. When the eggs of mosquitoes hatch, what comes out of 
them? 

11. Where do “wigglers” or “wiggle-tails” live? What do they 
breathe? How do they get air? How long do “wiggle-tails” live? 
What do they turn into? 

12. What happens to mosquitoes and wiggle-tails when the 
freezing weather of winter comes? 

13. What kind of mosquito spreads malaria? During what part 


132 PHYSIOLOGY, HYGIENE, AND SANITATION 


of the day does it do most of its flying and biting? Where does it 
lay its eggs? 

14. How may one keep from getting malaria? 

15. How are mosquitoes kept from multiplying? How are 
wiggle-tails destroyed? What is the purpose of destroying “wiggle- 
tails”? 

16. Why should houses be screened in places where there is 
malaria? 


CHAPTER XXV 


Tuberculosis 

1 uberculosis is a disease caused by microbes. The 
microbes may attack any part of the body. They often 
locate in a bone and cause the bone to become diseased. 
However, they most frequently attack the lungs and cause 
the disease known as pulmonary tuberculosis or consump¬ 
tion. About one tenth of all deaths are due to this disease. 
In the United States alone about 150,000 persons die of it 
each year. 

Where tuberculosis microbes come from. — Cattle have 
tuberculosis as well as people. The microbes of tubercu¬ 
losis live in people and cattle which have the disease. 
Whenever a person develops the disease, it is because he 
has got into his body tuberculosis microbes which have 
come from the body of some person or of some cow which 
has the disease. Most cases in people are due to microbes 
from other persons, but about one case in every ten is due 
to microbes from cattle. 

How the microbes get into our bodies. — When a cow 
has tuberculosis, the microbes often get into the milk, and 
people who drink it will get the microbes into their bodies. 
This is one of the reasons why all milk should be pas¬ 
teurized to kill whatever disease microbes may be in it. 

But most of the microbes which cause tuberculosis in 
people come from other persons. When people with con¬ 
sumption cough or sneeze, they often scatter the microbes 

133 



i 3 4 PHYSIOLOGY, HYGIENE, AND SANITATION 

about them. Some people in talking scatter little droplets 
of saliva from the mouth. If a person with consumption 
talks or coughs with his mouth directed towards another 
person’s face, he may actually scatter microbes on the 
other person’s face and into the air he is breathing. 

Persons with consumption usually cough up more or less 
sputum. The sputum usually contains tuberculosis mi¬ 
crobes. If they spit the sputum 
on the sidewalk or in places where 
people walk, people will get it on 
their shoes and perhaps carry it 
into their homes and get it on the 
carpets or rugs. Or flies may walk 
in the sputum and get it all over 
their feet, then fly to fruit or bread 
or other food and wipe their feet 
on it. Or perhaps the fly will 
fall into a pitcher of milk or get 

sumptive. The microbes StUck in the butter ' If this ba P' 
are the small, threadlike pens, anyone who eats these things 

spots and are as they ap- w jp get tp e microbes into his 
pear through a microscope. ° 

stomach. 

People with consumption often have the microbes in 
their mouths. When they drink from a cup or glass they 
may leave some of the microbes on it. If others use the 
cup or glass after them they will probably get the microbes 
into their mouths. This is one reason why we should not 
drink out of the common drinking cup so often seen in 
public places. It is better to go thirsty than to use such 
a cup. 

What a sick person should do to protect others. — A 

person with consumption should never cough or sneeze 


Microbes of 

CULOSIS 


As seen 
coughed up 


in 

by 


Tuber- 

sputum 
a con- 



TUBERCULOSIS 


T 35 


while facing another person. He should turn the head 
away and hold a handkerchief or piece of cloth in front of 
the mouth to prevent scattering the microbes all about. 
He should not talk with his face close to the faces of 
others. He should not spit where people can walk in the 
sputum nor where flies can get at it. It is better for him 
to spit into pieces of cloth or paper which can be burned 
or into a cup which he can carry in his pocket, if he wishes, 
and which can be either burned or emptied and disin¬ 
fected. 

People with consumption should not use cups or glasses 
which will be used by others. The cups, glasses, spoons, 
and forks which they use at meals should be scalded with 
boiling water after each meal. It would be well to scald 
also their plates and other dishes as well. Where there 
are children about they should be particularly careful, for 
children get the disease more readily than older persons do. 

People with consumption may find it tiresome and some¬ 
what of a nuisance to do all these things, but for the sake 
of those about them they love, and for the sake of others, 
as well, they should do them. No one would want to 
think he had given the disease to others, especially to a 
friend or some loved one. 

What we can do to keep from getting tuberculosis. — 

There are so many people who have tuberculosis, and 
many of them are so careless in regard to coughing and 
spitting, that the microbes of the disease are constantly 
being scattered about. As a result most people at some 
time or other get the microbes into their bodies. For¬ 
tunately, if our bodies are well nourished and healthy, 
they are able to destroy a few of these microbes. If our 
bodies are not strong and healthy, however, they may not 


136 PHYSIOLOGY, HYGIENE, AND SANITATION 


be able to destroy them, and even a few of the microbes 
may be able to multiply and start the disease. 

The surest way therefore to protect ourselves from 
tuberculosis is to keep our bodies strong and healthy. To 
do this we must eat the kinds of food the body needs, and 
must get enough outdoor exercise to keep the organs and 
tissues in good condition, and enough sleep each day to 
rest the body after its work and play. Sleeping outdoors 
or in a room with the windows open helps to keep the 
body healthy and strong. 

But if we keep getting the microbes into our bodies, or 
if we get many of them at one time, we may develop the 
disease even if our bodies are strong and healthy. We 
should be very careful when we are around people whom 
we know have the disease, especially if they do not know 
the dangers and are not careful to hold a handkerchief or 
cloth before their mouths when they cough, and if they 
are careless about spitting. 

Growing boys and girls should keep away as much as 
possible from those who have the disease and should keep 
their bodies healthy and strong. 

Questions 

1. What causes tuberculosis? What part of the body does it 
affect most often? 

2. Do many people die of this disease? About how many people 
die of it each year in the United States? 

3. Where do the microbes of tuberculosis live? How do people 
get tuberculosis? Can one have tuberculosis unless the microbes of 
the disease get into his body? Where do the microbes come from? 

4. How do people get tuberculosis from cows? Where do people 
most often get the tuberculosis microbe? 

5. How do people with tuberculosis spread the microbes to 


TUBERCULOSIS 


*37 

others? If a person has microbes in his mouth what becomes of 
them when he coughs, sneezes, or talks loudly? 

6. Should people talk into other person’s faces? Why not? 

7. Why is the sputum of a consumptive dangerous? Why 
should people not spit on the sidewalk or anywhere where people 
walk? 

8. How may the microbes of tuberculosis be spread by common 
drinking cups and water glasses? 

9. What should a person who has tuberculosis do to keep from 
giving the disease to others? What should they do when they 
cough or sneeze? Why? What precaution should they take when 
talking to other people? What should they do with their sputum? 
What should be done with the dishes from which they eat and 
especially those they put into their mouths? 

10. Do children or adults get tuberculosis the more easily? 

11. Can one’s body destroy the microbes of tuberculosis? Do 
many people get the microbes into their bodies? Does it make a 
difference whether one gets a few or many microbes into one’s body? 
Why? 

12. Does a strong, healthy body destroy the microbes of tuber¬ 
culosis better than one which is not strong and healthy? If a person 
with a strong, healthy body got a few microbes into his body what 
would probably happen to the microbes? If his body was not 
strong and healthy what might happen? 

13. What can we do to protect ourselves from getting tuber¬ 
culosis? 

14. What is almost sure to happen if one keeps getting the mi¬ 
crobes of tuberculosis into his body? 


CHAPTER XXVI 


Smallpox and Vaccination 

Smallpox is another disease caused by microbes. It 
spreads very rapidly from person to person. Many years 
ago it was a very common disease throughout most parts 
of the world. Almost everyone had it at some time during 
his life. It caused the deaths of a great many people. 
Those who had it and got well usually had their faces 
and bodies badly scarred and disfigured. It was a disease 
every one feared. 

In 1796, Edward Jenner, an English physician, showed 
that if a person was vaccinated with what was called 
cowpox he would not get smallpox even if he came in 
contact with people sick with the disease. This was a 
great discovery, because it made it possible for people to 
protect themselves from the dreaded disease. By the use 
of vaccination smallpox has now become a rare disease in 
many countries. It is still a common disease and each 
year kills many persons in those countries where the people 
have not been vaccinated. The disease will not spread in 
places where all the people have been vaccinated, and 
those living in such places do not need to fear it. For this 
reason the people in many countries are required by law 
to be vaccinated. In many places children are not allowed 
to attend school until they have been vaccinated. This is 
true in many parts of the United States, and as a result 
smallpox seldom occurs in these places. 

138 


SMALLPOX AND VACCINATION 


T 39 


Vaccination. — The outer surface of the left arm is the 
place usually chosen for vaccination. The skin is first 
cleaned with soap and water or a little alcohol. Then, 
when it becomes dry, a scratch is made with a clean needle 
or the point of a knife, and a drop of vaccine is gently 
rubbed into the scratch. Often two 
scratches are made about an inch apart. 

The scratch heals in a few hours, but 
after three or four days one or more 
little swellings appear at the place vac¬ 
cinated. These get larger after a day 
or two more, and have little blisters on 
them filled with pus, and the arm about 
them becomes red and a little swollen. 

Later a dry brown scab forms. When 
this falls off a little scar is left. Usually 
about the seventh day after being vac¬ 
cinated, when the arm is red and swollen, 
a person feels a little ill and has a little 
fever. This, however, lasts only about 
a day. It is an easy and simple way 
to protect oneself from such a serious 
and disfiguring disease as smallpox. 

Being vaccinated once will protect a 
person against smallpox for several years. If one is 
vaccinated again after five or seven years, he will usually 
be protected for the rest of his life and need not be 
vaccinated any more. However, it is a good plan to be 
vaccinated again, if one is where there is much smallpox. 

If every one in the world were vaccinated, smallpox 
would disappear entirely and cease to exist. It would 
then trouble us no more. 



A Vaccination 
Sore 


As it appears on 
the seventh day. 
This is what will 
protect you from 
smallpox. This scab 
will come off and 
leave a little white 
scar. 





140 PHYSIOLOGY, HYGIENE, AND SANITATION 

Questions 

1. Have you ever seen a person who has had smallpox? 

2. What causes smallpox? 

3. Was smallpox ever a very common disease? Did it kill many 
people? 

4. How can you tell a person who has had smallpox? 

5. Who was Edward Jenner? 

6. What did he discover? Why was his discovery important? 

7. Is smallpox a r^re disease now in many countries? Why? 

8. Is smallpox still a common disease in some countries? Why? 

9. Do people who have been vaccinated need to fear smallpox? 
Why not? 

10. Why does the law in many countries require people to be 
vaccinated? 

11. What part of the body is usually chosen for the vaccination? 

12. How is vaccination performed? 

13. Have you ever been vaccinated? If you have been, tell 
what happened to your arm. Did it make you feel sick at all? 

14. Would you rather be vaccinated or run the risk of having 
smallpox? 

15. How long will being vaccinated once protect one from small¬ 
pox? 

16. When should one be vaccinated a second time? 

17. How long will two vaccinations protect a person? 

18. What would happen if everyone in the world could be vacci¬ 
nated? 

19. Do you think it would be a good thing to have everyone in 
the world vaccinated, if this could be done? Why can not this be 
done? 

20. Would it be possible to have everyone in your city or town 
vaccinated? How would you have this done? 


PART III 


Hygiene or the Home 



CHAPTER XXVII 


The Home 

To the Arab his tent is his home. The home of the 
savage may be a grass hut. The winter home of the 
Eskimo of the Far North is a house of ice and snow. 
With us our home is the house in which we live. It is 
where we mingle most with those we love. It is where we 
eat and sleep and visit with father and mother, sisters and 
brothers. It should be a place of happiness and health, 
a place where our body machines can get the things they 
need, — good food, pure air, and plenty of sleep. It should 
be a place where disease microbes cannot reach us. 

If we live in a city, our home may be a number of rooms 
in a large building called an apartment, or flat, or it may 
be a house with a yard around it. If we live in a small 
town, it may be a house with a large yard, a barn, a wood¬ 
shed, and a garden. If we are fortunate enough to live on 
a farm, the house will be surrounded with fields, and 
there will be stables and outhouses and perhaps an orchard. 

The location of the house. — If one is selecting a house 
to live in, or if one is going to build one, the first thing to 
decide upon is the location. A house should be built 
where the land is dry. It should not be near swampy 
ground nor where puddles or pools of water form after 
rains. The best location is where the ground slopes away 
from the house in all directions. Then when it rains the 
water flows away from the house and leaves the ground 
about it dry. If the house were to be built in a hollow 

143 


144 PHYSIOLOGY, HYGIENE, AND SANITATION 


where the ground sloped toward it, the water would col¬ 
lect around the house and some of it would undoubtedly 
run into the cellar and keep it wet and damp. 

In cities the houses usually face the street, and in the 
country they are built to face the road. If the house 
faces north or south, east or west, the sun will shine into 
the windows of three sides at some time during the day, 
into the windows on the east in the morning, into those 
on the south during the middle part of the day, and into 
those facing west during the afternoon. But if the house 
is made to face northeast or northwest or southeast or 
southwest, the sun will shine into all the windows of the 
house. The windows on the sides towards the northeast 
and southeast will have sun during the morning, and those 
on the sides facing northwest and southwest will have it 
during the afternoon. It is best to have the house so that 
the sun will shine into all the rooms if one can. It makes 
the rooms brighter and more cheerful. 

What houses are built of. — Most houses with cellars 
have the cellar walls made of brick or stone. Many 
houses also have the walls of the house built of brick or 
stone. But most houses in America have the house walls 
built of wood. It is best to have the cellar walls built of 
brick or stone, as this gives a solid foundation upon which 
to build the house, but for that part above the cellar, 
wood makes as good a house as any, except that it is more 
likely to catch on fire and burn than is a house built of 
brick or stone. Houses built of wood are called “frame” 
houses. Stone and brick houses are more likely to be 
damp than are wooden ones. Bricks and stone absorb 
water when it rains and will remain damp for a long time. 

All houses are plastered on the inside to make the walls 


THE HOME 


!45 


smooth. It also makes the walls thicker and the house 
warmer. Plaster is made of sand and lime and sometimes 
with cement added. 

The roofs of houses are built mainly to keep out the rain. 
They are slanted so that the water will run off rapidly 
instead of leaking through into the house. Wooden shingles 
are most often used to cover the roof. Sometimes slate is 
used. The pieces of slate are much like those used in 
school and are put on so that they overlap, just as is 
done with wooden shingles. Slate is not so likely to catch 
fire as are shingles. In some parts of cities they will not 
let people put wooden shingles on their houses because 
of the danger of fire. Often in cities the roofs are covered 
with sheet iron coated with tin and painted. These are 
called tin roofs. They have the advantage that they will 
not catch fire, but they get very hot in summer and may 
make the upper part of the house uncomfortably warm. 

The cellar or basement. —- The cellar is an important 
part of the house. It should be so built that it will keep 
dry. If it is damp, the house itself will be damp. If the 
cellar is built where the ground stays wet, tile drains 
placed in the ground outside of the cellar wall will carry 
the water away and keep it from running into the cellar. 

If the house has a furnace for heating, it is usually 
placed in the cellar. The cellar also furnishes a place to 
store the fuel used in the furnace, —- the coal or wood. 
Vegetables and canned fruits are also usually kept there. 
The cellar should be kept clean, and rubbish should not 
be allowed to collect in it. Rubbish in a cellar may catch 
fire and is dangerous for this reason. Besides, rubbish 
should not be allowed to collect in any part of the home, 
and the cellar is part of the home. 


146 


PHYSIOLOGY, HYGIENE, AND SANITATION 


Questions 

1. What is a home? 

2. What is the Arab’s home? The Eskimo’s? 

3. What should the home be? 

4. What kind of land should a house be built upon? Which 
way should the ground slope, towards the house or away from it? 
Why? 

5. What happens when a house is built in a hollow? 

6. How can a home be built so that the sun will shine into all 
the windows during some part of the day? 

7. Why would you like to have the sun shine into all the rooms? 

8. What are cellar walls usually built of? Why? 

9. What are houses built of? 

10. In what way is a wooden or “frame” house better than one 
built of brick or stone? 

11. What advantage has a brick or stone house over a “frame” 
house? 

12. What is plaster made of? Why is it put in houses? 

13. What are the roofs of houses made of? In what way are 
slate roofs better than those covered with wooden shingles? 

14. Why should a house have a dry cellar? How can a cellar 
be made dry? 

15. What are cellars used for? Why should they be kept clean? 


CHAPTER XXVIII 


Heating the Home 

Heating the home. — In the tropics and where it is 
warm all the year round, houses do not need to be heated. 
But in most parts of the United States it is so cold during 
the winter that some kind of heat is necessary. Some 
people use stoves to heat the house, some have hot air 
furnaces, some use steam, and some hot water. 

Stoves. — Stoves furnish plenty of heat, but do not heat 
all the rooms. Usually the rooms in which there are stoves 
are very warm, especially near the stoves, while the 
other rooms may be cold. If there are several stoves 
in a house, it requires considerable work to keep them 
supplied with coal or wood and to clean away the ashes. 
For this reason most people prefer to have in the cellar 
a furnace which will heat all parts of the house and will 
make it necessary to take care of only one fire. 

Hot air furnaces. —• Many houses are heated by hot air 
furnaces. The furnace is placed in the cellar and is sur¬ 
rounded by a sheet-iron jacket. There is a space between 
the furnace and the jacket. When the furnace gets hot it 
heats the air in this space. Leading from this space, 
called the hot-air chamber, are large pipes which go to 
each room of the house. When air is heated it becomes 
light and rises, so that as the air in the hot-air chamber 
becomes warm it flows up the pipes and into the rooms 
above. The hotter the air the faster it flows. As the hot 


147 


148 PHYSIOLOGY, HYGIENE, AND SANITATION 


air in the chamber flows up the pipes to heat the house, 
cold air flows into the chamber through a large pipe which 
lets in cold air from outdoors. This cold air is heated in 
the chamber around the furnace and then flows up into 
the house above. In this way fresh cold air from outdoors 

is constantly flow¬ 
ing . into the cham¬ 
ber, and then being 
heated flows up into 
the rooms above. 

Houses can be 
heated very well in 
this way, but the 
pipes which carry 
the warm air must 
be large enough and 
must slant upward 
or the warm air will 
not flow through 
them and some 
parts of the house 
will not be warmed. 
Sometimes when 
the wind is blowing 
from a certain direc¬ 
tion it interferes 
with the flow of the warm air and makes it difficult to 
heat the house. A hot-air furnace costs less to put in 
than does a furnace which heats by steam or hot water. 

Heating by steam. — In houses heated by steam the 
furnace is also usually placed in the cellar. While the hot¬ 
air furnace has a chamber in which air is heated and sent 



Heating with a Furnace — Hot Air 
System 









































































HEATING THE HOME 


149 


through pipes to all parts of the house, the steam furnace 
has a chamber in which water is heated and changed into 
steam, and the steam flows through pipes to radiators in 
the various rooms. The steam heats the radiators and 
keeps them hot, 
and the radiators 
warm the house. 

The steam does 
not flow out into 
the air of the 
rooms as the hot 
air from the hot¬ 
air furnace does. 

The steam stays in 
the radiators, and 
when it becomes 
cold it changes 
again into water 
and flows back to 
the water chamber 
of the furnace. It 
is often easier to 
heat a house by 
steam than by hot 
air because the steam is under pressure and can be made 
to flow where it is wanted. However, as soon as the fire 
in the furnace gets low so that it will not make the water 
in the chamber boil, no steam is formed and there is no 
heat for the house. With a hot-air furnace there is some 
flow of warm air through the pipes as long as there is fire. 

Heating by hot water. —* In heating with hot water the 
furnace has a chamber with pipes leading from it to 



Steam-Heating System 

























































































150 PHYSIOLOGY, HYGIENE, AND SANITATION 

radiators in the rooms of the house just as when steam is 
used. But with hot-water heating the chamber and the 
pipes and the radiators are all filled with water. When 
water is heated it rises to the top just as air rises when it 

is heated. The result 
is that when the furnace 
heats the water in the 
chamber, the hot water 
rises up through the 
pipes and into the radi¬ 
ators so that the radi¬ 
ators become hot. As 
the water in the radiator 
becomes cooled, it flows 
back to the furnace 
through other pipes and 
is again heated. In this 
way the water is con¬ 
stantly flowing through 
the pipes. Hot water 
flows to the radiators, 
and the cooled water 
flows back to the furnace. 

The pipes and radiators have to be larger when hot 
water is used than they do with steam, so that a hot- 
water heating system costs more than a steam-heating one. 
However, a hot-water system keeps a house at a more uni¬ 
form temperature than does steam, because as long as the 
furnace fire is going the water stays warm. The water 
cools more slowly than steam. It takes longer to get a 
cold house warmed up with water than with steam, but 
once warmed it is kept warm more easily. 
















































HEATING THE HOME 


i5i 

Houses should not be kept too hot. — People in America 
usually heat their houses much hotter in winter than do 
people in the countries of Europe. This may be because 
in America coal and wood are much cheaper and more 
plentiful than they are in Europe. Houses should not be 
heated too hot, because one is more likely to catch a head 
cold when one goes outdoors where it is cold after being 
in a house that is too warm. Breathing the hot, dry air 
of a house makes the mucous membranes of the nose and 
throat less healthy and less able to withstand and fight the 
microbes which cause head colds. 

In order to keep a house properly heated and so one may 
know whether it is too cold or too warm, thermometers 
should be hung in the different rooms. If one has but one 
thermometer, it is best to have it in the living room or 
sitting room where the family gathers to visit or to read 
or to study. What is known as the Fahrenheit thermom¬ 
eter is the one usually used in America. The living room 
is the one that should be kept warmest, for this is where 
the members of the family spend most of their time when 
they are sitting quietly reading or talking. This room 
should be heated to from 68° to 72 0 as shown by the 
thermometer. This will be found comfortable. If it gets 
warmer than this, the air will be too hot and dry. The 
dining room where the family eats should be the same 
temperature at mealtime. Rooms where people are not 
sitting quietly need not be so warm as this. The bed¬ 
rooms at night should be much cooler. In fact, in them 
the heat can be shut off and the windows opened so that 
during sleep the air breathed is cool. We sleep better 
when we have cold air to breathe, and we wake up in the 
morning feeling more refreshed. 


152 PHYSIOLOGY, HYGIENE, AND SANITATION 

The air in heated houses is dry. — The air in heated 
houses is usually very dry, drier even than desert air. In 
cold weather the air has very little moisture in it, for cold 
air will not hold moisture. When cold, dry, winter air 
is heated, as it is in our houses, it becomes exceedingly 
dry, and when we breathe it, it dries and irritates the 
membranes of our noses and throats. If we could only 
moisten the air, it would make us feel much more com¬ 
fortable, and it would be pleasanter to breathe. When 
people heat their houses by stoves, they often place a 
kettle or dish of water on the stove, and as the steam 
passes oh from this it helps to moisten the air a little. 
Hot-air furnaces have a small water tank connected with 
the hot-air chamber. This tank should be kept filled, as 
it gives some moisture to the dry, heated air. Sometimes 
cans of water are hung behind steam and hot-water radia¬ 
tors to give off moisture. All these things help some, but 
none of them make the air as moist as it should be. The 
hotter the air in the room is heated, the drier it gets and 
the more moisture it should have. This is one reason why 
we should not heat the air of our houses too hot. 

Questions 

1. How are houses heated? How is your school heated? 

2. How warm should a house be heated? How warm is your 
school room heated in the winter? 

3. Why should a house not be heated too warm? How does a 
too warm house make one more likely to catch a head cold? 

4. Do you study better at school when the room is hot or when 
it is cool? Do you get sleepy when you study in a hot room? 

5. What is a thermometer? Have you one in your school room? 

6. Is heated air dry? How dry may the air in a heated house 
become? Do you like to breathe dry air? 


CHAPTER XXIX 


The Home (Continued) 



The bedroom where we sleep. —* We spend at least a 
third of our lives in our bedrooms sleeping. It is here we 
spend from eight to ten hours each day. The bedrooms 
should be cool at night. While sleeping the body should 
be kept comfortably 
warm with blankets 
and quilts if necessary. 

If too much covering 
is used, the body will 
be too warm and sleep 
will not be so refresh¬ 
ing. The head should 
not be covered, but 
should be out where 
cool air can be 
breathed. If the head 
is covered by the 
blankets, one breathes 
and rebreathes the 

same warm air over and over again. Not only is it best 
to have the head uncovered, but the windows of the room 
should be opened enough so that the air in the room is 
kept cool or even cold. 

Many people sleep on open porches. People nowadays 
often build porches on their houses for sleeping. When we 

153 


A Sleeping Porch 




























































154 PHYSIOLOGY, HYGIENE, AND SANITATION 


have slept on a sleeping-porch we seldom ever want to sleep 
in a bedroom again except when the weather is very cold. 
One seems to sleep better on an outdoor porch and to 
wake up feeling more refreshed. Of course it is simply 
because the air is usually cooler outdoors and is constantly 
in motion, carrying away the air that has been breathed 
and bringing always fresh, cool air to the sleeper. If one 
has plenty of windows in his bedroom and keeps them 
open, he can have almost the same condition he would 
have on a porch, but most people who have slept on porches 
like it much better than sleeping in bedrooms. 

The kitchen. — The kitchen is the room which is usually 
used more than any other in the house. It is here that 
the food is prepared and the meals cooked. In the kitchen 
a large part of the work of the house is done. Because it 
is used so much, the kitchen should be made one of the 
pleasantest rooms. It should have plenty of windows to 
give light and air. Instead of being the room to which 
least attention is paid, it should be planned with the 
greatest care. The stove and sink and tables should be so 
placed that they will make the work in the kitchen as 
easy as possible. The icebox and pantry where the food 
is kept should be where they can be reached conveniently. 
As the food is prepared and the meals cooked in the 
kitchen, everything should be so arranged that the room 
can be easily kept clean. 

The kitchen is the housekeeping workshop. The pans 
and dishes and cooking utensils are the tools. Every good 
workman takes pride in his tools and shop and keeps 
them in the best of condition. Every good cook properly 
takes pride in her kitchen and the utensils which are her 
tools. The work of preparing food for the family so that 


THE HOME 


155 


it will be pleasant to eat and easy for the body to digest 
is as important as any work one can do, and the ability 
to do it is a great accomplishment. 

Screening of windows and doors. — Flies are a nuisance 
and carry microbes on their dirty feet, and mosquitoes 
bite and annoy one even where they do not carry malaria. 
For this reason a house should have all the windows and 
doors covered by screens to keep out these insects wherever 
they are present. In hot climates flies and mosquitoes are 
present during all the year. In most parts of the United. 
States, however, they are present only during the summer 
and disappear after the first freezing weather in the 
autumn. 

The screens should be made to cover the windows, and 
the door screens should be made so to fit the doors that 
neither flies nor mosquitoes can get in. Cloth netting is 
often used to cover windows. It will keep out flies, but 
usually the meshes are so large that small mosquitoes can 
get through them. Cloth netting is likely to get torn and 
soon wears out. Many use netting of iron wire painted. 
This rusts and holes form in it after it has been used for a 
year or two. A better netting and one which lasts longer 
is made of galvanized iron wire. Galvanized wire is iron 
wire coated with zinc. The netting which lasts longest is 
made of copper or bronze wire, but this is quite expensive 
and often costs so much it cannot be used. However, it 
will last many years, and because it lasts so long is often 
really the cheapest. 

Any of the kinds of netting used will keep out flies, but 
some of them have meshes so large that small mosquitoes 
can get through, especially the small mosquitoes which 
carry malaria. Where there is malaria the holes of the 


156 PHYSIOLOGY, HYGIENE, AND SANITATION 

screen should be small, not larger than one eighteenth of 
an inch across. Screens as fine as this will have eighteen 
meshes to the inch. Some screens are made with meshes 
as large as one twelfth of an inch across. These are large 
enough to let mosquitoes get through them. Flies and 
mosquitoes are our enemies. They endanger our health. 
The house is a place for the family to live in, and all dan¬ 
gerous insect enemies should be kept out. 

Lighting the home. —• A house should have plenty of 
windows. Every room should have at least one window 
and if possible two or three. The windows let in light 
during the day. The more windows there are, the lighter 
and more cheerful the house will be. In warm weather 
the windows can be opened to let in the breezes and cool 
the home. 

The sun lights our houses during the day, but when it 
gets dark at night we have to have some other means of 
lighting. Otherwise we would have to go to bed before 
it got dark. Years ago people had only candles to light 
their houses, but now we have lamps which burn kerosene, 
and people in the cities have gas and electricity. What¬ 
ever form of lighting is used, when we are reading or 
studying the light should shine on our book so that we 
can see the type easily. It should not shine into our eyes. 
If it does it will tire them. It is better to have the light 
shine over the left shoulder on to the book, or if the light 
is in front of us on a table, it should be so shaded that 
the light itself cannot be seen. 

Daylight tires the eyes less than artificial light does, so 
we ought to do as much of our studying as possible during 
the daytime, but when the days are short and the evenings 
are long, as they are during the winter, we have to do some 


THE HOME 


157 


of our reading at night. However, in reading and study¬ 
ing we should always think of our eyes and make sure the 
light is good, for we can never have but the one pair of 
eyes. 

Questions 

1. How many hours a day do you spend in bed? How much of 
your lifetime do you spend in bed? 

2. What kind of air should one breathe while asleep? Does a 
bedroom need to be heated? Do you have your bedroom windows 
open at night? Do you like them open? Do you feel better in the 
morning when you have slept in a cool room or in a warm one? 

3. What happens if one covers one’s head at night with blankets 
or quilts? Why should one not do this? 

4. Why do some people sleep on sleeping porches? 

5. Is the kitchen an important part of the house? Why? Why 
is the kitchen the home workshop? 

6. Why should a house be screened? What is used for screening? 

7. What kind of screening do you think is best? 

8. How fine does screening need to be to keep out the mosqui¬ 
toes which carry malaria microbes? How many holes or meshes to 
the inch should it have? How would you tell how many meshes 
there were to the inch in a screen? 

9. Why are windows built in houses? What purposes do they 
serve? 

10. How are houses lighted during the day? How are they 
lighted after dark? 

11. Why do we need to have our houses lighted? 

12. When we are reading or studying how should the light shine 
on our book? Do you like to face a light? Does it hurt your eyes? 
Can you read better when the light is back of you and shines over 
your shoulder? 

13. Can one read more easily by daylight or by lamplight? 
Which tires the eyes more? 

14. When should one do as much of his reading or studying as 
he can? 


CHAPTER XXX 


The Home (Continued) 

The floors of the house. — The floors of houses are 
made of wood. Usually narrow boards are used which 
fit closely together and make a smooth floor with the 
narrowest possible cracks. The smaller the cracks the 
better. Some floors are so well made they have no cracks 
at all. Floors without cracks are much easier to keep 
clean, for when there are cracks, dirt gets into them and. 
cannot be swept up. Soft wood, such as pine, is often 
used for floors, but many use hard wood, such as oak and 
maple. Floors made of hard wood last longer and keep 
in better condition. 

Some people have their floors bare, but many cover 
them with carpets or rugs. Bare floors are easier to keep 
clean, but carpets and rugs make the house quieter so that 
one does not make so much noise as when walking over a 
bare floor. However, carpets and rugs collect dirt. Often 
we bring dirt into the house from out of doors on our feet. 
This gets into the carpets, and in time they become very 
dusty and have to be cleaned. For this reason many 
people use on their floors rugs which can be easily taken 
outdoors and swept and dusted. If carpets are used and 
are tacked down to the floor, as they often are, it is very 
difficult to take them up and clean them. Many people 
prefer to use rugs for this reason. 

Care of Garbage. — In the preparation of food there 

158 


THE HOME 


159 


is always some waste, such as the parings of potatoes and 
other vegetables, egg shells, and the skins of fruit. The 
waste parts of food are called garbage. On a farm it can 
be fed to chickens and hogs, but in cities this cannot be 
done. It cannot be thrown into the yard, for it will at¬ 
tract flies and rats, and in warm weather it will get 
“smelly” and unpleasant. It can be wrapped in paper or 
be put in a paper sack and burned in a fire. But this is 
not always convenient, especially in summer, when the 
only fire is the one in the cook stove. Another way to 
get rid of garbage is to bury it in the ground. 

In all the larger cities and in many of the smaller ones 
the city employs men to go around to the houses and get 
the garbage and carry it away. These men call at the 
houses once or twice a week in winter and usually oftener 
in the summer, sometimes every day. Each house has to 
have something in which to keep the garbage until it is 
called for. Whatever it is kept in should be water-tight 
and have a tightly fitting cover so that flies, rats, cats, and 
dogs cannot get to it. If it is left open, it will attract 
flies and rats to the house. If dogs and cats can get at it, 
they will very likely upset it and scatter it about the 
yard. Galvanized iron cans with tightly fitting covers are 
made for holding garbage and are used by most people. 
In buying such a can one should be sure the cover fits so 
well that flies cannot get into the can and that dogs can¬ 
not knock it off. 

The men who are employed by the city to collect the 
garbage from the houses usually have wagons with water¬ 
tight boxes into which it is put and carried off. If the 
boxes are not tight, the liquid part of the garbage would 
leak out into the street and besides being untidy would 


i6o PHYSIOLOGY, HYGIENE, AND SANITATION 


attract flies. The garbage that is carried away is usually 
burned or fed to hogs. 

Stables. —- If one keeps a horse or cow and has a stable, 
unless he takes special precautions he will find that in 
warm weather there will be thousands of flies about. Flies 
lay their eggs in stable manure. The eggs hatch out. 
From each egg there comes a maggot called a larva. In a 

few days each maggot develops 
into a fly. If one were to want 
to raise flies, keeping a pile of 
stable manure would be the best 
way to do it. But we do not 
want flies about our houses. 

If we could keep the stable 
manure in a box or bin with a 
cover that fitted so tightly that 
flies could not get in to lay their 
eggs, it would be all right. But 
this is difficult to do. It is hard 
to make a cover fit so closely 
that flies cannot get in. One can 
prevent flies from breeding by 
sprinkling over the manure borax or chloride of lime or 
kerosene. But the best way is to have the manure taken 
away once a week and carried to a field or farm where it 
can be used as fertilizer. If the stable is kept clean and. 
the manure is taken away each week, flies will not breed 
in it. If this is not done there will probably be so many 
flies hatched out that they will become a nuisance to all 
the people living in the neighborhood. 

The yard. — If one lives in a house with a yard one is 
fortunate. Many houses in the cities have no yards, or 



Larv^; or Maggots 


From which flies develop. 
Flies lay eggs in stable manure. 
The eggs hatch into maggots. 
Each maggot develops into a 
fly. 


THE HOME 


161 


perhaps all they have is a small yard behind the house. 
If one keeps one’s house clean he will undoubtedly keep 
his yard clean and attractive, for in a sense the yard is a 
part of the home. If garbage is allowed to collect in the 
yard it will breed flies. If tin cans and other refuse are 
allowed to collect, they look unsightly. If trash collects, 
it may catch on fire and endanger the house. You can 
usually tell what kind of people live in a house by looking 
at the yard. 

Outdoor toilet. — In cities and towns where there are 
sewers people have toilets in their bathrooms, and the 
body wastes are carried away through the sewer. Where 
there are no sewers people have outdoor toilets. These 
are usually placed in the yard a distance back of the 
house. These need to be built with care and kept as clean 
as any part of the house. One must remember that flies 
feed on filth wherever they can find it as well as on the 
food on our tables, if they can get into our houses; also 
that in feeding they will soil their feet and may soil our 
food with the dirt from their feet. The little dark spots 
which flies leave on windows and walls, and on our tables 
as well, are the body wastes of the flies which they eject 
from their intestines. 

Not only should the house be screened to keep out 
flies, but the outdoor toilet should be screened just as 
carefully. It would be fortunate if there were no flies in 
the world, but as long as we have them we must do what 
we can to keep them from doing us harm. 


162 PHYSIOLOGY, HYGIENE, AND SANITATION 


Questions 

1. What are the floors of houses made of? What are they 
covered with? What do you think of using rugs and carpets on the 
floors? Which do you think is better? Why? 

2. What is garbage? 

3. What should be done with garbage? Why? 

4. What may be done with garbage if one lives in the country? 

5. How is garbage taken care of in the cities? 

6. What happens if the garbage is thrown out on the ground in 

the yard? » 

7. Why are there likely to be many flies in the neighborhood of 
a horse or cow stable? 

8. Where do flies like to lay their eggs? When the fly eggs 
hatch what comes out of them? What do the maggots (or larvae) 
turn into? 

9. If one wanted to raise flies what would be the best way to 
do it? 

10. How may flies be prevented from laying their eggs in stable 
manure? 

11. What is the best way of taking care of stable manure so that 
flies will not hatch in it and become a nuisance and a danger? 

12. What can you say about how a yard should be kept? Why? 

13. Why should outdoor toilets be properly built and well cared 
for? Why should they be screened? 

14. When you see a fly, do you stop to think where the maggot 
probably lived from which the fly came or upon what the fly may 
have been feeding an hour before? 


PART IV 


Community Hygiene and Sanitation: or 
What our City and State Govern¬ 
ments Can Do to Protect Our Health 



CHAPTER XXXI 


How We Get Good Milk 

Of all the things we eat to nourish our bodies, cows’ 
milk is the most important. It is the best food for babies 
who are not nursed by their mothers. It should constitute 
a large part of the diet of growing boys and girls. It 
furnishes lime and substances which are not present in 
sufficient amount in other foods. It is valuable in smaller 
amounts as food for grown men and women. Babies eat 
little else than milk. Growing boys and girls need a quart 
of milk a day. Most grown men and women should drink 
a pint a day. 

We learned in previous chapters that disease microbes 
may sometimes get into milk if it is not properly handled. 
Milk is our most valuable food, but to be good it must not 
contain living disease microbes. Fortunately disease mi¬ 
crobes are quickly killed by heat. Much of the milk sold 
in cities is heated for this purpose and so is perfectly safe. 
The process of heating milk is called pasteurization. 
When you buy milk which is labelled “Pasteurized,” you 
know it has been heated to kill any disease germs which 
might have accidentally got into it. 

Milk is an animal product. It comes from cows. Other 
animal products, such as meats and fish, are cooked before 
they are eaten. Milk is usually not cooked. It is eaten, 
or rather drunk, raw. To be sure, milk is heated when it 
is pasteurized, but it is not heated so hot that you would 

165 



166 PHYSIOLOGY, HYGIENE, AND SANITATION 

say it was cooked. For this reason we want milk from 
healthy cows, and we want it handled in a cleanly way 
and kept free from dirt. 

Some people have their own cows. — People who live 
on farms and many who live in small towns keep their 
own cows to supply them with milk. They can have just 
as clean, good milk as they want. They know whether 


A Clean Barn and Barnyard 
The cows are also clean. 

(From Bulletin 56, Hygienic Laboratory.) 

their cows are healthy and can be sure that the milk pail 
is clean and that in milking dirt from the cow or from the 
stable does not get into the milk. As they are the only 
ones who handle the milk, they know that the disease 
microbes from others cannot get into it. 

Where people in cities get their milk. — But with 
people in cities it is different. They cannot keep their 
own cows. The milk they use must be brought in from 
• farms out in the country. The milk for a city may come 




HOW WE GET GOOD MILK 167 

from a thousand farms or for a large city from ten thou¬ 
sand farms. Some of these farms may be located many 
miles from the city, and the milk may be shipped in 
on trains. When it reaches the city it is usually put 
into bottles and delivered to the houses by the “ milk¬ 
man.” 

If the milk for a city comes from a thousand farms, it 
has been handled by people in a thousand families on 
these farms. There are usually about five people in a 
family, so that in the thousand families there would be 
five thousand people. The milk would be exposed on the 
farms to the diseases of five thousand people. Some of 
them might have diphtheria or scarlet fever, or perhaps 
typhoid fever, or be just recovering from one of these 
diseases, and some of their microbes might get into the 
milk and be carried to the people in the city. This is 
why most milk used in cities is pasteurized to kill any 
disease microbes there may be in it. 

Good microbes in milk. — If milk is not kept in the ice 
box it soon turns sour. Certain microbes in it cause it 
to sour. These microbes are always present in milk, and 
when the milk is allowed to get warm the microbes multi¬ 
ply until there are many millions of them in a teaspoonful. 
As they grow and multiply they change the sugar in the 
milk into an acid called lactic acid. This is what gives 
milk a sour taste. It is this acid also that causes the 
milk to curdle. We said the microbes change the sugar to 
acid. All milk has some sugar in it. The sugar in milk, 
however, is not sweet like the sugar you buy at the store. 
The sweet sugar you buy at the store is called “cane 
sugar.” The sugar in milk is called “lactose.” 

The microbes which turn milk sour are not harmful. In 


168 PHYSIOLOGY, HYGIENE, AND SANITATION 


fact they may be thought of as good microbes. Butter¬ 
milk, which many people drink and like, is usually sour 
and contains millions of these microbes. 

How disease microbes may get into milk. — But un¬ 
fortunately there are also certain disease microbes which 
can live and multiply in milk. These are the microbes of 
typhoid fever, diphtheria, scarlet fever, and of a severe 
kind of sore throat called septic sore throat. If people 
with any of these diseases milk the cows or handle the 



Milk seen through a Microscope 
A , Clean milk, showing no germs. B , Dirty milk, containing many germs. 

milk at any time, their microbes may get into the milk. 
If their hands are dirty, the microbes may get into the 
milk when they milk the cows. Or they may sneeze or 
cough over a pail of milk and microbes from their mouths 
may fall into the milk. If the milk is cooled as soon as it 
comes from the cow and is kept cold, these microbes will 
not multiply, although they will remain alive. But if the 
milk is allowed to get warm the microbes will multiply, 
and although only a few may have got into the milk, they 
may become millions in a short time. 


HOW WE GET GOOD MILK 


169 


There is another disease the microbes of which get into 
milk. Cows have tuberculosis just as people do. Milk 
from cows with the disease contains the microbes of tuber¬ 
culosis. Milk that is to be used by people should come only 
from healthy cows. Fortunately there is a way that the 
farmer can tell whether any of his cows have tuberculosis. 
It is called “the tuberculin test.” A small amount of the 
poison of the tuberculosis microbe is injected beneath the 
skin of the cow, and if the cow develops a fever within a 
few hours, it shows that the animal has the disease. If the 
cow is healthy, no fever will develop. If the cow has 
tuberculosis, its milk should not be used by people. 
Usually the cow is killed. All good farmers who sell milk 
for people to drink test their cows in this way. In many 
cities milk is not allowed to be sold unless it comes from 
cows which have been tested and are known to be free 
from tuberculosis. This helps to keep our milk safe. 
Then, too, the microbes of tuberculosis and of the other 
diseases are killed by the method of heating called pas¬ 
teurization of which we have told previously. Pasteuriza¬ 
tion is the one sure way we have of killing any of the dis¬ 
ease microbes which may have got into the milk. Dead 
microbes do us no harm. Properly pasteurized milk is 
safe milk and the best and cheapest of foods. 


Questions 

1. What is the most important food? Why? 

2. What is milk? Where does it come from? 

3. Where do the people in cities get their milk? 

4. What makes milk turn sour? Are the microbes which turn 
milk sour harmful? 

5. What disease microbes may get into milk? 


170 PHYSIOLOGY, HYGIENE, AND SANITATION 

6. How do disease microbes get into milk? 

7. What disease do cows have of which microbes may get into 
milk? 

8. How can it be told whether a cow has tuberculosis? 

9. How may the microbes in milk be kept from multiply¬ 
ing? 

10. How may the disease microbes in milk be killed? 


CHAPTER XXXII 


How We Get Good Milk (Continued) 

How milk should be produced; healthy cows. — Milk 
intended for people to drink should come only from healthy 
cows. The cows should be healthy in every way. They 
should not have tuberculosis or any other disease. All 
cows in the herd should be tested for tuberculosis once or 
twice a year. The cows must also be properly taken care 
of. Like people, if cows are to remain healthy, they must 
be kept clean, have a good place to sleep, have good air 
to breathe, good water to drink, and be given proper food 
to nourish their bodies. Out in the West where the herds 
of cattle live on the plains and are in the open air all the 
time, the cattle are usually healthy; they are seldom sick 
and almost never have tuberculosis. But when cows are 
kept shut up in barns and sheds and get little exercise, 
they have to be specially well cared for or they will get 
disease. In this way they are like people. 

The barn or stable in which cows are kept should have 
plenty of windows so that the animal w r ill get clean, fresh, 
cool air to breathe. The cow should be kept clean, and 
the stables too. Not only will cleanliness help keep the 
cows healthy, but it will make it possible to get clean 
milk. It is impossible to get clean milk from a dirty cow 
in a dirty stable. Sometimes where people do not know 
how to produce good milk, they let their cow-stables get 
very dirty. But one does not see dirty stables so often 


172 PHYSIOLOGY, HYGIENE, AND SANITATION 


now as one did many years ago before people knew what 
was necessary to produce good milk. Many city health 
departments send men out to inspect the cows and the 
stables on farms producing milk for sale in the city. These 



A Modern Dairy 

The barn is clean; the cows are clean; and the men have on clean white 
suits and caps. A place like this produces the cleanest milk. 


men see that the cows are healthy and that the stables 
are kept clean. 

Milking. — Milk when taken from the cow is milked 
into a pail. The cow should be first cleaned, for if the 
cow is dirty, dirt will fall into the pail. The milkers’ 
hands should be clean, for if they are dirty some of the 
dirt will be washed into the milk. Many people use a 
pail with a small top, because the smaller the top of the 









HOW WE GET GOOD MILK 


173 


pail the less chance there is for dirt to fall in. At many 
of the best dairies the cows’ udders are washed clean 
before being milked, and the men who do the milking 
first wash their hands and put on clean white suits. Milk 
produced in this way is almost sure to be clean. 

Handling milk on the farm. — After the milk is taken 
from the cow it is usually strained through cheesecloth 
or a fine strainer to remove any particles of dirt which 
may have accidentally fallen into it. It should then be 
cooled if possible and kept cold, for when kept cold milk 
keeps better and does not sour, and the microbes in it do 
not multiply. Before being used the milk pails and the 
cans in which the milk is kept should have been washed 
clean with soap and water and then scalded with boiling 
water to sterilize them, that is, to kill any microbes which 
might have been in them. If this is not done, the pails 
and cans will be dirty and will contain many microbes, and 
the milk will not keep well. 

Getting milk to the city. — For large cities the milk 
has to come from many farms, and some of them will be 
many miles away. The milk from these farms may be 
hauled to the city in wagons if the farms are not too dis¬ 
tant. Often nowadays motor trucks collect the milk from 
a number of farms and carry it rapidly to the city. Fre¬ 
quently the milk is shipped to the city on trains. The 
important thing is to get it to the city just as quickly as 
can be done and to keep it cold while it is on the way. 

What becomes of the milk when it reaches the city. — 
When the milk reaches the city it usually goes to a large 
city dairy. Here it is run through a machine which takes 
out all the dirt. Then it is pasteurized to kill any disease 
germs that may have got into it from the cows, or from 


174 PHYSIOLOGY, HYGIENE, AND SANITATION 

the people who did the milking, or from those who handled 
it on the farms, or while it was being taken to the city. 
Then it is put into bottles which have been washed and 
sterilized in boiling water. The paper caps are put into 
the tops of the bottles and the milk is cooled. In many 
well-equipped dairies, the bottles are filled and the paper 



A Sanitary Bottling Room 

Here milk is kept pure by absolutely clean handling. Notice the 
clean, white clothing of the men. 


caps are inserted in the tops by machine so that no one’s 
hands come near the milk after it is pasteurized. Later 
the milk is delivered in the bottles to the homes of the 
people who are to use it. The milk is usually delivered 
by wagons in the early morning so the people will have 
fresh milk for their breakfast. 

Medical inspection of persons handling milk. — Many 














HOW WE GET GOOD MILK 


T 75 


city health departments in order to protect us still further 
from the possibility of getting disease microbes in milk, 
examine the people who handle the milk in the dairies, to 
make sure they have no disease of which the microbes 
might be spread by the milk. 

Care of milk in the home. — If the milkman delivers to 
our houses good clean milk free from disease microbes, we 
must not let it get contaminated in our houses. Milk 
keeps best if it is not allowed to get warm. If it gets 
warm the microbes in it grow and multiply and turn the 
milk sour. Milk should be kept where it is cold. In warm 
weather it should be kept in an ice-box. When it is removed 
from the bottles it should be poured only into clean dishes. 
Flies should not be allowed to get near it, or, worst of all, 
into it. The milk should not be handled by a person who 
is sick with a microbe disease, and no one should cough 
or sneeze over milk in a pitcher or dish, for if he does he 
will spray into it sputum and microbes from the mouth. 

Care of empty bottles. — When milk is delivered to 
people in bottles, the empty bottles have to be returned 
to the milkman so that they can be used again. When 
emptied the bottles should be washed clean and kept 
clean until returned to the milkman. Food should not be 
put into them, nor should they be used for any other 
purpose. We must help the milkman keep the bottles 
clean. He will wash and scald them before he puts milk 
into them again, but if they are very dirty it may be 
difficult for him to get them as clean as they should be. 
We want our milk brought to us in clean bottles and so 
do other people. 

Milk sold in small towns. — In towns and small cities 
often the milk is brought to the houses by the farmers 


176 PHYSIOLOGY, HYGIENE, AND SANITATION 


who produce it on their farms. They bring the milk in 
from the farm each morning and deliver it to the houses. 
Usually it is not bottled, but is dipped from a large can, 
and each family takes to the wagon the pail or pitcher 
into which the milk is poured. This milk is not pasteur¬ 
ized. Sometimes the town or county health officer in¬ 
spects the farms to see that the cows are healthy and the 
stables kept clean, but very often he has not had time to 
do this. If the milkman has healthy cows and keeps his 
stables clean and is careful about handling the milk, the 
milk is pure and clean. If this is not so, the milk may be 
dirty and not the kind one should drink. People who 
buy milk from a farmer should visit his farm and see how 
he keeps his cows and whether he knows how to keep the 
milk clean. 

Milk can be made safe by boiling just as water is. 
Boiling kills any disease microbes there may be in it. But 
most people do not like boiled milk. The boiling changes 
the taste. 

Milk our most important food. — In the cities the 
health departments control the sale of milk, and, in so far 
as they can, see that only good milk is sold. Bottled 
pasteurized milk is usually the safest and best. In small 
towns each family often has to be its own health depart¬ 
ment and see that the milk it gets is clean and comes 
from healthy cows. It is as necessary that the dairyman 
be clean and use clean pails and cans for his milk as it is 
that the person who cooks and prepares our food is clean 
and uses clean dishes. 

. Milk is our most important food, and when we consider 
the nourishment and necessary substances it furnishes the 
body, it is our cheapest food. 


HOW WE GET GOOD MILK 


177 


Questions 

1. Why should milk from healthy cows only be sold? 

2. Why should cows be kept clean? Why should cow stables 
be kept clean? 

3. Why should a cow not be milked by a person with dirty 
hands? 

4. Why should milk always be kept cold? 

5. Does your milkman leave your milk in bottles? 

6. What can you say about how milk should be taken care of 
after it has been delivered by the milkman? Why should it be kept 
cold and clean? 

7. Why should empty milk bottles be washed and kept clean? 

8. Why is properly pasteurized milk the safest kind to drink? 


CHAPTER XXXIII 


Water — What It Is; the Need for Good Water and 

How to Get It 

We must have water to drink, but we need it also for 
many other purposes. We use water to bathe in and in 
washing our hands and faces. Our clothes are washed in 
water. Water is used in cooking and for washing the 
dishes from which we eat. Floors and windows are washed 
with water. When we have bathrooms in our houses, we 
must have water piped in so that it will flush the toilets. 
Then, too, factories and manufacturing establishments 
often use large quantities of water. 

People live only where there is water. — People do not 
live where they cannot get water. Cities can grow only 
where there is sufficient water available to furnish the 
people with what they need. In desert regions where 
water is scarce the people will always be found living near 
the springs or other sources of water. The presence or 
absence of water determines where people can live. Water 
is as necessary as food, but if it becomes polluted it may 
be harmful. If sewage gets into it, it may spread disease 
such as typhoid fever. 

Where water comes from. — All water may be thought 
of as coming from rain or snow. Water vapor rises from 
the surface of the sea and lakes and rivers, forms clouds, 
and later falls as rain. The water falling as rain either 
sinks into the ground or flows along the surface into a 
stream and finds it way finally back to the sea. 

178 


GOOD WATER AND HOW TO GET IT 


179 


Water is made up of two elements combined together. 
These are the gases oxygen and hydrogen. If an electric 
spark is passed through a mixture of two parts hydrogen 
gas and one part oxygen gas, water is formed. Pure 
water is clear and has no odor or taste. It is very diffi¬ 
cult, however, to get absolutely pure water, for water 
takes up many substances with which it comes in contact. 
It dissolves not only such substances as sugar and salt, 
but takes up gases as well. Even rain as it falls absorbs 
gases from the air. 

When rain falls to the earth and then runs over the 
surface and into a stream or river, it carries with it a 
certain amount of earth, decaying vegetable matter and 
other dirt. Most of this soon settles, however, as the 
stream flows along, and the water becomes clear again. 
If the water sinks into the ground, it may pass over or 
through mineral substances, such as limestone or iron or 
sulphur deposits, which it will dissolve. Limestone makes 
water hard, that is, soap curdles in it. Iron and sulphur 
give it an unpleasant taste, as all know who have drunk 
the water from iron or sulphur springs. 

Some water is unsafe to drink. — Water is not safe to 
drink when it has become polluted with sewage. Sewage 
may get into river or lake water when cities or towns or 
even farm houses empty their sewage into the stream or 
lake. Sewage may get into a well when the surface of the 
ground is polluted and the rain washes the pollution into 
the well or when an outdoor privy is placed too near the 
well. The chief danger in drinking water polluted with 
sewage even in a small amount is that we may contract 
typhoid fever, for typhoid fever is carried by sewage. 
Microbes of typhoid fever pass into the sewage from the 


180 PHYSIOLOGY, HYGIENE, AND SANITATION 


bodies of persons sick with the disease. If the sewage 
gets into wells or into springs or rivers, people who drink 
the water are likely to get typhoid fever. There has been 
a great deal of typhoid fever in the United States in the 
past, especially in the cities and towns. Much of it has 
been due to the fact that the water used by the people for 
drinking was polluted by sewage. 

Rainwater. — Rainwater is sometimes used for drink¬ 
ing. The rain as it falls is good water and perfectly safe 
to drink. If it is collected from the clean roofs of houses 
and stored in properly built cisterns, well covered so that 
neither dirt nor animals can get in, the water will be free 
from harmful substances. Such cisterns should always be 
so covered that mosquitoes cannot get in, for if they do 
they will lay their eggs on the water. These will later 
hatch and finally develop into full grown mosquitoes. In 
this way we may breed in our own yards enough mos¬ 
quitoes to make ourselves and our neighbors miserable. 

Wells. — People living on farms and in small towns 
usually get the water they need from wells. A well is a 
hole made in the earth extending down until it reaches 
water. This water in the earth is the rain which has 
sunk into the soil instead of running off into streams. 
The water usually sinks down through the earth until it 
comes to a hard layer of rock or clay. It can then go no 
farther, but stays in the earth above this layer, or stratum 
as it is called. If a hole is made down to this, the water 
will run into the hole and can be pumped up. 

If a well is not over thirty feet deep it is called a sur¬ 
face well. Surface wells are usually dug with spades and 
shovels, and are holes from four to six feet in diameter. 
If the water is to be used for drinking, the sides of the well 


GOOD WATER AND HOW TO GET IT 181 

should be lined with brick, stone, or terracotta tile. The 
joints between the brick or stone or tile should be filled 
with cement mortar. This lining wall of the well is called 
the casing. It should extend up above the surface of the 
ground for at least a foot, so that rain cannot run into the 
top of the well and carry in dirt 
from the surface of the ground. 

The top of the well should be 
tightly covered so that neither 
drippings from the pump nor rain 
can get in. A tight cover also 
keeps out animals. If a well is 
not so covered, cats and dogs 
and sometimes rats will fall in 
and drown. Their bodies are 
often not found, and remain in 
the well. It is not pleasant to 
think of drinking water from 
such wells. 

When a well is dug it should 
be placed as far as possible from, 
stables and outdoor privies, es¬ 
pecially from any privy which is 
merely a hole in the ground like 
the well, for the contents of the 
privy may soak through the 
ground and get into the well. Water from a well polluted 
in this way is dangerous and not fit to drink. 

Some wells are made by drilling small holes very deep 
in the earth, sometimes several hundred feet or even 
deeper. These holes usually pass through one or more 
hard layers or strata through which the water from the 



A Properly Built Well 

The top is above the surface 
of the ground, and is tightly 
covered. The casing of the 
well is made of terracotta tile 
with tight joints. 



























182 physiology, hygiene, and sanitation 


earth cannot pass. The holes are lined with iron pipes 
and the water is pumped up. Such a well is called a drilled 
well, and the water is usually very good and safe. It 
should be carefully covered at the top, however, just as is 
done w T ith shallow w^ells, so that neither w r ater nor animals 
can get in. Sometimes in a deep well of this kind the water 



Croton Dam 

This is one of the dams that hold back water for the supply of 

New York City. 

will come to the surface and flow out of the top. When it 
does this it is known as an artesian well. 

Sometimes wells are made by driving iron pipes into the 
earth until water is reached. Pumps are then put into 
the pipes to bring the wrater to the surface. These are 
called driven wells and are much like the drilled wells. 
They should be carefully covered at the top. 

Public water supplies. — In most cities water is fur¬ 
nished to the houses from a public water supply, so that 
wells are not needed. The water is usually pumped through 






GOOD WATER AND HOW TO GET IT 183 

pipes, and there is a small pipe leading to each house. If 
you want water all you have to do is to turn on the faucet. 

The water furnished in this way by cities should be 
good water and not polluted by sewage or the people will 
get typhoid fever. Some small cities get all the water 
they need by digging or drilling a number of big wells, but 
most cities have to get their water from lakes or rivers. 
Sometimes a city can get safe water by extending water pipes 
up to the mountains where nobody lives and where a stream 
can be found in which the water is pure and free from sew¬ 
age. This water can be brought to the city in large pipes. 

However, most cities have to get their water from rivers 
or lakes into which other towns and cities often empty 
their sewage. Sometimes a city empties its own sewage 
into the lake or river from which it gets its water. Such 
water is polluted and is unsafe to drink. It must be 
purified in some way. Usually it must first be allowed to 
stand in a large reservoir so that most of the mud and dirt 
will settle to the bottom, then the water is passed through 
some kind of a filter. Filters in which the water passes 
through sand are the ones most frequently used. The 
sand takes out not only the dirt, but most of the germs 
which get into the water with the sewage. Some cities 
have to put chloride of lime into the water to make it 
safe to drink. The chloride of lime kills any typhoid 
microbes which may be in the water. 

A city sometimes has to spend a great deal of money 
to get enough pure water for the people, but it is far better 
to spend the money for good water than it is to have 
many cases of typhoid fever. Then, too, plenty of good 
water means it will be easier for people to be clean. With 
plenty of water they can have a bath as often as they 


184 PHYSIOLOGY, HYGIENE, AND SANITATION 


want, and there will be plenty of water for washing clothes 
and other things about their homes. 

If water is polluted and unsafe to drink, we can always 
make it perfectly safe by boiling it. The boiling will kill 
any disease microbes there may be in it. 

Questions 

1. What is water used for? 

2. Why do people always live where they can get water? 

3. Where does water come from? Where does the water in 
snow and rain come from? 

4. What is pure water like? 

5. Why is it difficult to get pure water? 

6. What makes water hard? What is meant by hard water? 

7. When is water unsafe to drink? 

8. What disease is most often spread by drinking water polluted 
with sewage? 

9. When is rainwater safe to drink? 

10. Why should cisterns in which rainwater is stored be kept 
covered? 

11. What is a surface well? 

12. How should a surface well be made? Why? 

13. Why should a well wall, or casing, extend up above the 
surface of the ground and be tightly covered at the top? 

14. What is a drilled well? What is a driven well? 

15. How can the water in wells become polluted and unsafe to 
drink? 

16. Where do cities usually get the water furnished to the people? 

17. What precautions must be taken by a city to get pure 
water? Why? 

18. Where does your city get its water? Is it pure water and 
safe to drink? Does your city have to filter its water or put chloride 
of lime into it? 

19. Why do cities sometimes have to spend much money to get 
pure, safe water? 

20. How can water always be made safe to drink? Why does 
boiling make water safe? 


CHAPTER XXXIV 


Sewage, What It Is and How Disposed Of 

People who live in cities usually have toilets in their 
houses to carry off the waste products of the body. They 
also have bathtubs which empty when the stopper is 
pulled out, and sinks in the kitchen into which dishwater 
is poured. Where does all this dirty water and waste 
matter go, and what becomes of it? It flows through 
pipes into a sewer, and it is called sewage. The sewer 
carries it away. Do you know where the sewers of your 
city empty? 

Why sewage may be dangerous to health. — Sewage 
contains the waste products from houses and of the people 
who live in them. It contains not only the dirty water 
from washing dishes, floors, and clothes, but also sputum, 
excrement, and other body wastes. Where many people 
live, as in a city, there will be some who are sick with 
such diseases as typhoid fever, and the waste products 
from their bodies will be filled with the microbes of this 
disease. The sewage will contain these microbes, and if 
the sewage should get into the water which is used for 
drinking purposes and the microbes should still be alive, 
those drinking the water would get typhoid fever. 

How sewage is carried away in cities. — In cities the 
dirty water from houses and the waste products from 
people’s bodies are carried away in sewers. In each house 
the pipes from the sinks, bathtubs, and toilets all empty 

185 


186 PHYSIOLOGY, HYGIENE, AND SANITATION 


into one large pipe which extends under the ground from 
the house to the street, where it empties into a still larger 
pipe. The pipe in the street is called a street sewer, and 
it receives the sewage from all the houses along the street. 
The street sewers empty into still larger sewers, which 
finally carry the sewage to some river or lake into which 
it flows. 

In cities the rain that falls and the water from melting 
snow have to be carried off or they would form puddles 
and ponds. This water is also carried away by sewers. 
Sometimes it is carried off by the same sewers that carry 
the sewage from houses. Sometimes separate sewers are 
built to carry off the rainwater. You have noticed how dur¬ 
ing a rain the water will run along the streets, and usually 
when it reaches a corner flows into a hole. This hole is 
sometimes at the edge of the pavement and sometimes 
opens under a sidewalk. The water which enters this hole 
runs down into the sewer, where it is carried away. While 
the rainwater which enters the sewer is dirty water from 
the streets, the sewage from houses carries in it body 
excrement and disease microbes. 

Where sewers empty. — Sewers from cities usually 
empty, as has been said, into a river or lake. Cities also 
often get their drinking water from rivers and lakes, some¬ 
times from the same river or lake into which they empty 
their sewage. For this reason there have been a great 
many cases of typhoid fever in some cities. The microbes 
of typhoid fever in the excrement of the sick have been 
carried by the sewers to the river or lake where they 
would get into the water supplied to the people of the city 
for drinking. Many of the people who drank the water 
would then develop typhoid fever, so that the sewers 


SEWAGE 


187 

carried the microbes away, and the drinking water brought 
them back. Because of this many people were sick all 
the time. Fortunately typhoid microbes do not live very 
long in water, but many die in a few days and most of 
them within a month. 

Sometimes one city empties its sewage into a river and 
it flows down the river to where another city gets its 
drinking water. Ihen the people of the second city will 
have typhoid fever unless they purify the water by filter¬ 
ing or in some other way. 

How some cities purify their sewage. — To keep from 
polluting the rivers and lakes into which they empty their 
sewage with body excrement and disease microbes, many 
cities purify their sewage to remove most of the substances 
and microbes from it. This is done sometimes by letting 
the sewage flow into reservoirs where the solid parts settle 
to the bottom and only the fluid part flows on. Some¬ 
times it is run through a screen which takes out all the 
larger solid parts. Sometimes the sewage is allowed to 
remain for a time in tanks where the good microbes de¬ 
compose the solid matter in the sewage and kill most of 
the disease microbes. Sometimes it is passed through 
coarse filters of broken stone and sand. Sometimes one, 
sometimes several, of these methods are used by a city to 
make its sewage less unpleasant and less dangerous before 
it empties into the river or lake from which it and perhaps 
other cities take their drinking water. 

Sewage in small towns. — Small towns often have no 
sewerage systems to carry off the dirty water and body 
wastes from the houses. In places where they have no 
sewers, the people usually let the water from kitchen 
sinks and bathtubs run out on to the ground or into a 


188 PHYSIOLOGY, HYGIENE, AND SANITATION 

ditch near the house, and instead of having toilets in the 
houses, they have outdoor toilets in the yards to receive 
the excrement and the body wastes. 

Outdoor toilets. — People often do not understand that 
outdoor toilets may be the cause of spreading disease to 
themselves and to others unless they are properly built 
and taken care of. As a result outdoor toilets frequently 
are poorly built and neglected. If the body wastes from a 
person with typhoid fever get into the outdoor toilet, or 
privy, as it is often called, the microbes of the disease 
may pass through the ground with water and get into a 
well if there is one near. Then people who drink the water 
from the well may get the disease. Or flies may get at 
the excrement and get the microbes on their feet and legs 
and carry them to the tables and food of all the people 
living in the neighborhood. 

There is no part of the house that should be given 
more attention than the outdoor toilet. There is none 
that is more important to the health and welfare of the 
family and of the people living in the neighborhood. If 
there are wells anywhere near, the toilet should be so 
built that the body wastes, and the microbes in them, 
cannot soak into the ground, and it should be so screened 
that flies cannot get in. Every opening should be covered 
with screening. The door should fit tightly, and there 
should be no crack big enough to let a fly get through. 

Often buckets or cans are placed under the toilet seats 
to receive the excrement, which is kept covered with 
ashes, or lime, or even dry powdered earth. The cans are 
then taken away every few days and the contents buried 
where they will not do harm. This is a very good and 
convenient way of taking care of an outdoor toilet. 


SEWAGE 


189 

It is well known to physicians that people who go away 
in the summer to summer resorts often return home with 
typhoid fever. This is usually because they have been to 
a place where the people had outdoor toilets which were 
not properly built and were taken care of poorly or per¬ 
haps not taken care of at all. Somebody with typhoid 
fever, or it may be someone who had recently had the 
disease, was at the resort, and the flies carried the mi¬ 
crobes from the toilet used by him to the food of many 
people who were spending their vacation there. This is 
one reason why many people get the disease at summer 
resorts. 

Many people take pride in keeping their houses clean 
and in order. Where outdoor toilets are used they should 
be given as much attention as the kitchen or any other 
part of the house. 


Questions 

1. What is sewage? What are sewers? 

2. Why may sewage be dangerous to health? 

3. Where do the sewers of cities usually empty? 

4. Where do the sewers of your city empty? 

5. Why do some cities have many cases of typhoid fever? 

6. How do some cities partly purify their sewage? 

7. In places where they have no sewers, how do the people 
get rid of waste water from the houses? How do they dispose of the 
body wastes? 

8. Why may an outdoor toilet be dangerous? 

9. What can you say about how an outdoor toilet should be 
built? Why should it be screened? Why should it not be near a 
well? 

10. Why do people who go to summer resorts often return home 
with typhoid fever? 



CHAPTER XXXV 


The City Health Department and What It Does 

Cities have fire departments to protect the people from 
fires. If a house gets on fire, the fire department im¬ 
mediately sends its trucks and men who put out the fire 
and prevent it from spreading to other houses. If it were 
not for the fire department, the house would probably 
burn down and the fire would often spread to other houses 
and the loss would be great. If there are people in the 
burning building, the firemen get them out. In this way 
the fire department protects us and our houses from fire. 

Cities have police departments to protect the people 
from burglars and other evildoers. The police enforce 
the laws made for the protection of the people. They 
protect us from those who would steal the things which 
belong to us and from those who would do us injury. 

Cities have health departments to protect the people 
from disease. People can do a great deal to protect them¬ 
selves from disease, but there are many things that they 
cannot do, and there are many things the health depart¬ 
ment can do for them better and more easily than they 
could do them for themselves. 

We have learned how disease microbes may get into 
water and milk and disease be spread, how flies and mos¬ 
quitoes may spread disease, and how people who are sick 
may spread disease to others. The health department 
looks after the water and sees that it is safe, looks after 

190 


THE CITY HEALTH DEPARTMENT 


191 

the milk and sees that it is not contaminated, keeps flies 
and dangerous mosquitoes from breeding, and sees that 
sick people do not go about spreading disease to others. 
The health department tries to make it possible, in so far 
as it can, for people to be strong and healthy and keep 
free from disease. City health departments are very busy 
doing many things for us. 

What a city health department consists of. — In some 
cities there is what is called a board of health. Where 
there is a board of health, it has supervision over the 
work of the health department. A board of health usually 
consists of from three to nine members. The members of 
the board are in most cases physicians. Many of the 
boards also have engineers and lawyers on them. These 
boards do not themselves carry on the work of the health 
department but decide what work shall be done and some- ' 
times how it is to be done. Usually the members of the 
board are appointed by the mayor of the city. In only 
a very few cities do the members of the board receive any 
pay for their work. It is considered an honor to be ap¬ 
pointed a member of the board of health and help protect 
the lives and health of the people. The members of the 
board do not have to give all of their time to the work. 
The board meets from time to time and the members talk 
over the work of the health department and decide what 
needs to be done. 

The health officer. — All cities have a health officer who 
is in charge of the work of the health department and sees 
that the things the board of health wants done are carried 
out. The health officer is usually a physician. Except in 
the smallest cities, he spends all his time attending to the 
work of the health department and is paid for his work. 


192 PHYSIOLOGY, HYGIENE, AND SANITATION 


Except in the smallest cities, he has many men and women 
working under him doing the things that have to be at¬ 
tended to. 

Control of communicable diseases. — You learned in a 

previous chapter how some diseases are caused by microbes 
and how these diseases are spread from one person to 
another by microbes from the sick. To keep these diseases 
from spreading precautions have to be taken to prevent 
the microbes in the mouths and bodies of sick people 
from getting to well people or into their food or into the 
water or milk they drink. This is one of the things the 
health department has to do for us. In order to protect 
us they have to know which people have these diseases. 

How the health department finds out where there are 
cases of disease. — When a person is sick he usually has 
a physician come and see him. The physician comes and 
finds out what kind of sickness he has and what he needs 
in order to get well. The physician knows whether he has 
a disease that can be spread to others by microbes. For 
this reason the law requires that physicians report to the 
health department whenever they have a case of a dan¬ 
gerous microbe disease such as scarlet fever, measles, 
smallpox, diphtheria, or typhoid fever. 

What is done to prevent disease spreading from the 
sick to the well. — As soon as a case of one of these dis¬ 
eases is reported, the health department sends out a 
physician or nurse who knows what needs to be done to 
prevent the disease from spreading to other people. Some¬ 
times a sign is tacked up on the house so that people will 
know that there is a case of scarlet fever or diphtheria or 
smallpox in the house; whatever the disease is. Then 
people will not go in, for they will know that there is a 


THE CITY HEALTH DEPARTMENT 


193 

case of a communicable disease in the house. The sick 
person’s doctor and the health department physician or 
nurse work together. The sick person’s doctor takes care 
of him and sees that he gets well. The health depart¬ 
ment physician or nurse sees that precautions are taken so 
that the disease will not spread to others. The doctor cares 
for the sick. The health department protects the well. 

If the sickness is a case of diphtheria and there are 
children in the house, the health department will prob¬ 
ably give all the children antitoxin . This will keep them 
from getting the disease. Antitoxin is a substance which 
destroys the poison of the diphtheria microbe. It is in¬ 
jected beneath the skin and is carried by the blood from 
the place where it is injected to all parts of the body. It 
will stay in the body for several weeks, and during that 
time will protect a person from getting diphtheria. 

What is done to prevent disease spreading among school 
children. — If there are children in the house who go to 
school, the health department either has them stay out of 
school so that they will not carry the disease to other 
children in the school, or perhaps has them go and live 
in some other place. Then after they have stayed away 
long enough to be sure they have not caught the disease, 
they can go back to school without harming others. 

Sometimes the sick person is a child who has been 
going to school, and he may have been a little sick the 
last day or two he was at school. If this is so, he may 
have already spread his microbes to other children. Then 
the health department sends some one to the school to 
tell the teacher about it, and the children are watched 
from day to day, and if any of them appear to be getting 
sick, they are sent home until it is found out whether 


194 PHYSIOLOGY, HYGIENE, AND SANITATION 


they have the disease. In most microbe diseases a person 
does not get sick until several days after he has got the 
microbes into his body. The microbes have to multiply 
in one’s body for several days until there are millions of 
them before one feels sick. In scarlet fever and diphtheria 
it takes only a few days, sometimes only two days. In 
most diseases it takes longer. In measles and smallpox 
it usually takes about two weeks. 

What may be done if the disease is diphtheria. — If the 
disease i c diphtheria, the health department or the school 
physician may examine all the throats of the children in 
the room and find out whether any of them have diph¬ 
theria microbes in their mouths. Some children may have 
the microbes in their throats and not get sick, for some 
people do not get diphtheria. They are said to be im¬ 
mune, which means that their bodies have in them the 
substances which destroy the poisons of the diphtheria mi¬ 
crobe, so that it does them no harm and does not make 
them sick. However, people who are immune to diph¬ 
theria may carry the microbes in their throats and mouths 
and give them to others who will become sick. 

We now have a way of telling when a person is immune 
to diphtheria and need not fear the disease. It is called 
the Schick test. A very small amount of the poison of the 
diphtheria microbe is injected into the skin, usually into 
the skin of the arm. If the person tested is not immune 
and can get diphtheria, the skin in a day or two gets red 
around the place where the poison was injected. Then 
the redness disappears in a few days. If the person is 
immune, and will not get diphtheria, nothing happens. 
The skin does not get red. This is because there were 
substances in the body which destroyed the poison as 


THE CITY HEALTH DEPARTMENT 


195 


soon, as it was injected. Most men and women are im¬ 
mune to diphtheria, but only about half the school chil¬ 
dren are immune. 

If some of the children in a schoolroom get diphtheria, 
the health department or the school physician may want 
to give all the children in the room the Schick test so that 
they may know who can catch the disease and who can¬ 
not. Or if there are many cases, they may want to give 
the test to all the pupils in the school. In some cities 
most of the school children have been tested in this way. 

We said that some people are immune to diphtheria and 
need not fear the disease. All people can be made immune 
if they want to be. People are made immune by injecting 
beneath the skin a very small amount of the poison of the 
diphtheria microbe together with some of the substance 
which destroys the poison. Three injections are given a 
week apart. Then after a few weeks the person becomes 
immune, and will not get the disease even if the microbes 
get into his throat. In some cities the health department 
has made thousands of children immune to diphtheria in 
this way. These children do not need to fear diphtheria 
any more. 


Questions 

1. What is the purpose of a city health department? 

2. What does a city health department usually consist of? 

3. What is a board of health? What does it do? 

4. What does the health officer do? 

5. What do you understand by a communicable disease? Name 
some communicable diseases. 

6. In order to prevent the spread of communicable diseases, 
what does the health department need to know about the existing 
cases? 



196 PHYSIOLOGY, HYGIENE, AND SANITATION 


7. How does the health department learn where there are cases 
of communicable diseases? 

8. What can you say about the responsibility of physicians in 
reporting to the health department cases of communicable diseases? 

9. How does a physician endanger the lives of people when he 
fails to report a case of communicable disease to the health depart¬ 
ment? 

10. What should the health department do when a case of com¬ 
municable disease has been reported to it? 

11. Why does the health department tack signs on the houses 
where there are cases of certain communicable diseases? 

12. For what diseases does the health department put signs on 
houses in your city or town? What color are these signs or placards? 
Do you think that putting up these signs is a good thing? Why? 

13. What is the duty of a physician in taking care of a case of 
communicable disease? What is the duty of the health department? 

14. What may the health department do if there is a case of 
diphtheria in a house? 

15. If the person who has the disease is a boy or girl who goes 
to school, what may the health department do? 

16. If there are other children living in the house who go to 
school, what may the health department do to prevent the spread 
of the disease to other school children? Do you think this is a good 
thing to do? Why? 

17. If you were sick with a communicable disease, would you 
want to give it to others? Would you do all you could to keep 
from giving it to others? 

18. Does one get sick as soon as he gets disease microbes into his 
body? How long is it before one gets sick? Why? How long does 
it take in scarlet fever? How long in measles? 

19. May people have diphtheria microbes in their throats and 
not get sick? Why? 

20. What is meant when it is said that a person is immune to a 
disease? 

21. How can it be told whether a person is immune to diphtheria? 

22. Can people be made immune to diphtheria? How? 

23. How are people made immune to smallpox? 


CHAPTER XXXVI 


The City Health Department and What It Does 

(Continued) 

What will be done to prevent the spread of disease by 
milk. — If the disease which has been reported to the 
health department is one which can be spread by milk, 
the health department will probably see that the milk¬ 
man does not take empty milk bottles away from the 
house. He may leave milk, but will not be allowed to 
take empty bottles away. This is because some people 
are careless in the use of milk bottles. They use them 
for all sorts of things. The bottles may have microbes 
of the disease in them. If they are taken away and if the 
milkman should fill them again with milk without first 
sterilizing them in boiling water, the next people who got 
the bottles filled with milk might get the disease. If the 
milkman scalded the bottles in boiling water before put¬ 
ting fresh milk in them, there would be no danger. All 
good milkmen do this. There are some, however, who 
do not. 

If there is anyone living in the house with the sick 
person who works in a dairy or in a place where milk is 
sold, the health department will usually make sure that 
he has not got the disease, too, and will probably either 
have him stay home from work or else go somewhere else 
to live. If he continued to live at the house and each day 
handled milk which was to be used by others, he might 

197 


igS PHYSIOLOGY, HYGIENE, AND SANITATION 

carry the microbes to the place where he worked and get 
them into the milk. Then others might get the disease. 

What the health department may do to protect others 
living in the same house with the sick. — The work of the 
health department is to prevent the disease from spread¬ 
ing to other people. This includes other people living in 
the same house with the sick person as well as people who 
do not live in the house. Very often the best way to pro¬ 
tect the other people living in the house is to take the 
sick person to a hospital. When this is done there is no 
longer any danger of the microbes getting into the bodies 
of the other members of the family and giving them the 
disease. This is often necessary to protect the other chil¬ 
dren, brothers and sisters. Then, too, it is often best 
for the sick person, for at the hospital there will be nurses 
to watch over and care for him and physicians to see that 
he gets whatever he needs. Then when he is well again 
he can return home without there being any danger that 
he will give the disease to others. 

Sometimes the sick person can be taken care of at 
home, and then the doctor taking care of the case or the 
health department physician will have the sick one kept 
in a room with plenty of windows so that there will be 
enough air and the patient will be comfortable. The 
nurse or person taking care of the sick will be shown how 
to keep everything clean and how to prevent the microbes 
from getting to other parts of the house and to other 
members of the family. She will be told about washing 
her hands after handling the sick and what to do with 
the patient’s handkerchiefs and bedding and what to do 
with the dishes from which the sick one eats. It is un¬ 
pleasant to be sick, but when one is sick it is good to know 


THE CITY HEALTH DEPARTMENT 


199 

that one is being so taken care of that the disease will 
not be given to brothers and sisters. 

What the health department may do for persons having 
tuberculosis. — In most cities physicians report to the 
health department whenever they have a patient with 
tuberculosis. People with this disease are usually not so 
sick that they have to stay in bed. If they are in bed, the 
health department can send to them a nurse to see that 
they have everything they need. The nurse will tell them 
how to take care of their sputum and what to do so that 
they will not give their disease to others, if they have not 
already been told these things by their physicians. 

If they have not everything they need in order to get 
well, the health department will probably offer to send 
them to a hospital or a sanatorium where they can be well 
taken care of and where there will be physicians and nurses 
to see that they are given every attention and that every¬ 
thing possible is done for them so that they may get well. 
Then, too, if they go to a hospital or sanatorium there is 
no danger that the disease will be given to other members 
of their families, especially to children. Children catch 
the disease much more easily than do grown men and 
women. 

Most city health departments also have what are called 
dispensaries, where people with tuberculosis who have no 
physician of their own can go and be treated free by 
health department physicians, and can be told what to 
do to get well, and what to do to prevent spreading the 
disease to others. 


200 PHYSIOLOGY, HYGIENE, AND SANITATION 


Questions 

1. How can disease be carried by milk bottles? 

2. What does the health department do to prevent commu¬ 
nicable diseases from being spread from house to house by milk 
bottles? 

3. What can be done when there is a case of a communicable 
disease in a house, to prevent the other people in the house getting it? 

4. When should the sick person be taken to a hospital? Why is 
it sometimes better for the sick person when he is taken to a hos¬ 
pital? Why is it sometimes better for the other members of the 
family? 

5. What kind of a room should the sick person be put in? Why? 

6. When one is taking care of a person sick with a communi¬ 
cable disease, what precautions should be taken? Why? 

7. What precaution should be taken by one who has tubercu¬ 
losis to keep from giving the disease to others? Why? 

8. Why is it often better for a person with tuberculosis to go to 
a sanatorium? 


CHAPTER XXXVII 


The City Health Department and What It Does 

(Continued) 

What the health department may do for babies. — 

Most cities have what are called “infant welfare stations,” 
where mothers who have no physicians of their own can 
take their babies if they are sick and have physicians tell 
them what they need. Sometimes the baby needs medi¬ 
cine. Sometimes the baby is not getting the right kind 
of food. If this is so, the mother will be told just what to 
feed it. The mother can take the baby every few days 
and have it examined and weighed to see how it is getting 
along. If it needs specially prepared milk, the mother 
can usually get it at the welfare station or the physician 
there will tell her where to get it. 

What the health department does for the physicians of 
the city. — Most city health departments have labora¬ 
tories to which physicians can send samples of blood or 
sputum to be examined. If a person has a sore throat, 
the physician cannot always tell whether or not it is 
diphtheria or just a simple sore throat. The health de¬ 
partment will furnish the physician with little swabs of 
cotton attached to slender sticks and sealed in a glass 
tube. The physician will take one of the swabs and rub 
it over the sick person’s throat so that it will get on it 
some of the microbes from the throat. This is then rubbed 
over some jelly-like material in another glass tube and 


201 


202 


PHYSIOLOGY, HYGIENE, AND SANITATION 


sent to the health department, where the microbes are 
examined to find out whether they are diphtheria microbes. 
As soon as the microbes have been examined the health 
department reports to the physician what kinds were found. 

Or if a physician has a patient sick with a fever, he can 
send a little sample of the patient’s blood to the health 
department, and it will be examined to find out whether 
it contains the microbe of typhoid fever. 

Or if a physician has a patient who has a cough and is 
raising sputum, he may think that possibly his patient 
has tuberculosis. He can send some of the sputum to the 
health department, where it will be examined to see 
whether it contains the microbes of tuberculosis. The 
health department also makes examinations for other dis¬ 
eases. These examinations are a great help in this way to 
sick people and to physicians, for many physicians have 
not the time or instruments necessary to make these 
examinations for themselves. 

Then, too, the health department often examines in its 
laboratory the city water, that is, the water supplied to 
the people for drinking. It does this to make sure that 
the water is not polluted and does not contain the mi¬ 
crobes of diseases. 

Milk is also examined at the laboratory. The health 
department will buy milk from different milkmen and 
examine it to see that it is clean and that it has been 
carefully handled. All milk contains some microbes, but 
these are usually harmless. If the milk contains a great 
many microbes, the health department know T s that it has 
not been properly produced and handled. 

How the health department sees that only good milk is 
sold o — The milk which is sold in cities comes from farms 


THE CITY HEALTH DEPARTMENT 


203 


in the country. Many health departments have men who 
visit these farms to see whether the cows are healthy and 
the milk is kept clean and carefully handled. The dairies 
in the cities where the milk from the farms. is brought 
and bottled are also inspected to make sure that the milk 
is kept clean. In many cities the men who work at these 
dairies are examined to see that they do not have diseases 
that might be spread by the milk. Then, as we said be¬ 
fore, in many cities samples of milk are got from milk 
wagons, as it is about to be delivered to houses, and these 
samples are examined in the laboratory to make sure that 
only good, safe milk is being sold. 

How the health department watches over our food. — 
We learned in a previous chapter how some disease mi¬ 
crobes may get on the food we eat and how the microbes 
may be carried to the food by flies or may get into it if it 
is handled by persons who have certain diseases. In 
many cities the health department has men visit the places 
where food is handled and sold to see that flies are not 
allowed to get on it and that the people handling it have no 
disease of which the microbes might be carried to others. 
Among the places inspected are fruit stands, bakeries, gro¬ 
cery stores, candy stores, and meat markets. Hotels and 
restaurants are also inspected for the same purpose. 

Who pays the expenses of the health department. — 
The health department is maintained by the people to do 
all these things for them. A city health department costs 
a great deal of money, for all those who work for it have 
to be paid. The money to pay them comes from the 
taxes which people pay each year. Some cities have 
health departments which do all the things of which we 
have told. Others have smaller health departments which 


204 PHYSIOLOGY, HYGIENE, AND SANITATION 


do only some of these things. In cities where people 
want to be protected from disease as much as possi¬ 
ble, they have large, well managed health departments. 
People should know what their health department does, 
because it is their money that pays for the work. 

Questions 

1. What can the health department do for babies? 

2. What is an “infant welfare station”? 

3. What does the health department do to help the physicians? 
What is done at a health department laboratory? Do you think 
every health department should have a laboratory? Why? 

4. What can the health department do to prevent disease being 
spread by milk? 

5. Why should cows on dairy farms be inspected? 

6. Why should only farmers who keep their stables and cows 
clean be allowed to sell milk? 

7. Why should sick people not be allowed to milk cows or handle 
milk which is to be sold to others? 

8. Should the health department inspect the dairies in cities 
where milk is bottled and sold? Why? 

9. Should the health department inspect places where food is 
handled and sold? Why? 

10. What kinds of food need to be kept clean and away from 
flies? 

11. Why should flies be kept away from bread, fruits, meats and 
other foods? 

12. Is there any danger in allowing people who have communi¬ 
cable diseases to handle foods? Why? 

13. Why should the health department inspect restaurants and 
hotels? 

14. Does it cost much for a city to have a good health depart¬ 
ment? Who pays the money it requires to maintain the health 
department? 

15. Do you think every city should have a good health depart¬ 
ment? Why? 


CHAPTER XXXVIII 


The State Department of Health and What It Does 

In a preceding chapter we told of the work of the city 
health officer and health department. But only a part of 
the people live in cities. Many people live in small towns 
and in the country. People travel from one place to 
another and may carry disease. The food and milk used 
by the people of the city are produced on farms in the 
country. To protect the health of the people there must 
be a health department which can prevent the spread of 
disease in the country and small town and from country 
and town to cities and from one city to another. For this 
purpose state health departments have been created. 

What state departments of health are. — Like the city 
health department, a state health department usually con¬ 
sists of a board of health and a health officer. The board 
of health consists of several members, mostly physicians, 
but usually with a lawyer and engineer among its mem¬ 
bers. This board plans the work to be done and decides 
all important matters. The health officer sees that the 
work planned by the board is carried out. The members 
of the board and the health officer are usually appointed 
by the governor of the state. The members of the board 
receive little or no pay, as they are usually engaged at 
their own work and spend but a small part of their time 
in the work of the health department. The health officer 
spends all his time in the work of the health department 

205 


206 physiology, hygiene, and sanitation 


and is paid a salary. The health officer has many men 
working under him doing the many things necessary to 
protect the health of the people. 

Work of the state health department. — While the city 
health department has power to make regulations to be 
carried out only in the city, the state health department 
makes regulations to be carried out in all parts of the 
state. The city health department can control disease 
only in the city, but the state health department can con¬ 
trol disease everywhere in the state. The state health 
department knows what diseases are present in the state 
and where most of the cases are. When diseases become 
epidemic in any place in the state, it may send men to 
help the city or town health officers at the place. It 
sends men, if necessary, to aid in controlling the disease 
and to protect the people. In many states the state 
health department inspects all the farms where milk is 
produced for sale, to see that the cows are healthy and 
the stables kept clean. In some states it controls the water 
supplies of towns and cities, to see that the people have 
pure water to drink. The state health department fur¬ 
nishes help wherever it is needed to protect people’s 
health. In most states it also does all it can to teach 
people how to keep healthy. 

State health laws and regulations. — Every state has 
many laws the purpose of which is to protect the health 
of the people, for the health of the people is most impor¬ 
tant to any state. People who are not healthy are seldom 
happy. They cannot do good work and often cannot 
work at all. A man who is sick cannot earn the money 
his family needs. A woman who is sick has difficulty 
being as good a mother as one who is well. Every attack 


THE STATE DEPARTMENT OF HEALTH 207 

of sickness does some injury to the body machine. It 
may be but slight injury, or it may be great. It may be 
injury to the heart, or the kidneys, or the stomach, or 
the brain. The person who has been sick may feel per¬ 
fectly well again, but some injury has been done to the 
body machine, and the body machine is not quite so good 
as it was before. In this way attacks of serious illness 
shorten our lives, even though we recover from them. 
People wish to be strong and healthy and the state wants 
its people strong, healthy and happy. This is the purpose 
of state health laws, and this is the reason that there are 
health officers and health departments. 

The prevalence of disease. — One of the things usually 
required by the law of the state is that physicians must 
report to the health officer whenever they have a patient 
who has a disease which can be spread from one person 
to another. The most common of these diseases are 
diphtheria, leprosy, malaria, measles, meningitis, mumps, 
pneumonia, scarlet fever, smallpox, tuberculosis, typhoid 
fever, and whooping cough. 

The physician sends his reports of cases to the city 
or town health officer so that the health officer will know 
what kinds of communicable diseases are present in the 
city or town, how many cases there are, and where they 
are. If the health officer does not know what diseases 
are present, and how many cases there are, and where 
they are, he cannot do much to prevent the spread of the 
diseases, nor will he know when an epidemic is developing 
or when special precautions need to be taken. 

The town and city health officers report to the state 
health department the number of cases of the communi¬ 
cable diseases in each of their towns or cities. In some 


208 physiology, hygiene, and sanitation 


states they make these reports daily, in some states they 
report once a week. In this way the state health depart¬ 
ment knows at all times just how many cases of these 
diseases there are in each town or city of the state, where 
the diseases are increasing and where there are epidemics. 
It knows when the town or city health officers need help 
in controlling the diseases and can send whatever help is 
necessary. 


Questions 

1. Why are state health departments necessary? 

2. In what way do state health departments resemble the city 
health departments? 

3. What do the state health departments do? 

4. How do they help city health departments? 

5. What do they do for people in the country and small towns? 

6. How do state health departments learn what diseases are 
present in their states and where they are spreading? 

7. Do you think the work of the state health department is 
important? Why? 


CHAPTER XXXIX 


The United States Public Health Service 

The cities have health departments to look after the 
health of the people living in cities. Each state has a 
health department to look after the health interests of all 
the people in the state and to do the things city health 
departments cannot do. The national government at 
Washington has a health service, called the United States 
Public Health Service, to do the things which only the 
national government can do to protect the health of all 
the people. 

The work of the United States Public Health Service. — 

The United States Public Health Service works with and 
assists the state health departments whenever they need 
help. It keeps records of the prevalence of disease through¬ 
out the country, so that it knows just where diseases are 
most prevalent and where they are spreading. It pre¬ 
vents the bringing in of disease from foreign countries and 
the spread of disease from one state to another. When 
dangerous epidemics occur, it sends its experts to sup¬ 
press them. It maintains a laboratory, called the Hygienic 
Laboratory, where its officers are constantly studying dis¬ 
eases, their causes, and how to prevent them. 

How it watches the occurrence of disease. — We 
learned in a previous chapter how the physicians report 
to the city health officers the cases of communicable dis¬ 
ease among their patients, and how the city health officers 

209 


2io PHYSIOLOGY, HYGIENE, AND SANITATION 


forward the reports to the state health department, so 
that the state health officer will know what diseases are 
occurring in the state and where the cases are. 

The state and city health departments forward reports 
of the cases to the National Public Health Service at 
Washington. The city health departments report to 
Washington each week by mail the number of cases oc¬ 
curring in the cities. The state health departments report 
each week by telegraph the number of cases occurring in 
the states. In this way the Public Health Service knows 
at all times the prevalence of disease throughout the entire 
country. It publishes each week a bulletin telling how 
many cases of communicable diseases have been reported 
in all the cities and states and sends copies to the health 
departments of the cities and states, so that they, too, 
know where dangerous diseases are present and where 
they are spreading throughout the whole country. 

How it helps state health departments. — Whenever a 
state health department needs help, the Public Health 
Service will send specially trained men to work with it. 
Or whenever a disease becomes epidemic and is spreading 
from one state to another, it sends its officers to aid in 
controlling the epidemic and prevent its spread. Whenever 
plague or yellow fever or any specially dangerous disease 
has become epidemic, it sends it officers to help control 
the disease and stop its spread. 

Studies causes of disease. — While medical men have 
found the causes of many diseases and know how they are 
spread and what must be done to prevent them, there are 
still diseases of which we do not yet know the cause or 
just how they are communicated from one person to an¬ 
other. The Public Health Service has many trained men 


UNITED STATES PUBLIC HEALTH SERVICE 211 


who are busy studying these diseases. Some of these men 
work at the Hygienic Laboratory at Washington. Others 
are working in various parts of the country wherever the 
disease they are studying is most prevalent. 

Pellagra is a disease which has been common in the 
southern part of the United States for several years. The 
disease has been present in southern Europe and northern 
Africa for a long time. Yet we did not know what caused 
it. Some thought it was due to eating spoiled corn. 
Others thought it was due to a microbe which grew on 
com. The Public Health Service undertook to find out 
what caused the disease. It sent its officers to those parts 
of the country where there were the greatest number of 
cases. They found that the disease was due to people 
not eating all the kinds of food their bodies needed, and 
that people who drank milk and ate fresh vegetables and 
eggs did not have the disease. 

This Service has men studying leprosy, how it is spread 
and how it can be cured. These studies are carried on in 
the Hawaiian Islands, where there are many cases of the 
disease, and also at a hospital for lepers in Louisiana. 

What is done to prevent diseases from being brought to 
the United States from foreign countries. — There is yel¬ 
low fever in certain parts of Central and South America. 
Cholera and plague are present in parts of Asia. Typhus 
fever is present in eastern and southern Europe. These 
diseases are seldom present in the United States, although 
ships are constantly coming to our country from places 
where they are present. Whenever a ship comes from a 
foreign country, before it is allowed to come to the dock 
and let off any of its passengers, an officer of the Public 
Health Service goes aboard and examines the passengers 


212 PHYSIOLOGY, HYGIENE, AND SANITATION 


and members of the crew to make sure that none of them 
is sick with any of these dangerous diseases. If there are 
cases of disease aboard, the sick are taken care of and the 
ship is not allowed to let the passengers and crew land 
until there is no longer danger of spreading the disease. 

Examination of immigrants. — Each year there are sev¬ 
eral hundred thousand people who come to the United 
States from foreign countries. Most of them come here 
to live. They gre called immigrants. When they arrive 
in this country, they are examined by physicians of the 
Public Health Service to find whether they have diseases 
which they might spread to others. If an immigrant has 
a disease which can be cured in a short time, he is kept 
in a hospital until he is well. If the disease is one which 
will last a long time, the immigrant is sent back to the 
country from which he came. 

The Public Health Service is always studying how dis¬ 
eases can be prevented and what things can be done to 
make the people of our country healthier. It is at all 
times ready to cooperate with and help city and state 
departments of health, when such help is needed to pro¬ 
tect the health of the people. 


Questions 

1. What does the United States Public Health Service do? 

2. How does it learn what dangerous diseases are present in our 
country and where they are spreading? 

3. What does it do to help city and state health departments? 

4. What can you say about how the United States Public Health 
Service is constantly studying diseases and how to prevent them? 

5. How does it prevent dangerous diseases from being brought 
to this country by ships from foreign countries? 


CHAPTER XL 


Why Births and Deaths Are Recorded 

Recording of births. — Almost everywhere in the United 
States, the law requires that whenever a baby is born 
the fact shall be recorded with an official known as a 
registrar. The principal facts which usually have to be 
recorded are: the name of the child, whether boy or girl, 
the date and place of birth, and the names of the parents. 

It is very important that each child’s birth be recorded 
in this way. A child may want to go to school, and the 
teacher may think the child is not old enough. If the 
child’s birth has been recorded, the parents can show just 
how old the child is. 

In many states boys and girls are not allowed to go to 
work until they have reached a certain age, usually 14 or 
16 years. It may be necessary for a boy to go to work 
to earn money. If his birth was recorded, he can prove 
whether he is old enough. If his birth was not recorded, 
he may not be able to do this. 

In many states young men and women cannot get mar¬ 
ried without their parents’ consent unless they have reached 
a certain age. For this reason men and women often want 
to prove how old they are. If their births have not been 
recorded it may be very difficult. 

A boy may want to enlist in the army or navy. He may 
want to show that he is old enough. His birth record will 
show just how old he is. 

A person may want to vote. One cannot vote until one 

213 


214 PHYSIOLOGY, HYGIENE, AND SANITATION 


is twenty-one years old. The sure way to prove whether 
one is old enough to vote is by the birth record. 

In some places people do not understand the great im¬ 
portance to the child of having its birth officially recorded, 
and unfortunately the births of many children have not 
been recorded. They will have difficulty if they ever want 
to prove how old they are. They may even at some time 
have difficulty proving who their father and mother were 
or that they were born in the United States and are there¬ 
fore citizens of this country. 

Recording of deaths. — Deaths of people are also re¬ 
corded with the registrar. Usually the law will not permit 
a body to be buried in a cemetery until the death has been 
properly recorded. The record of the death shows the 
name and age of the person and the cause of death. 

If the person who dies left money or property, the 
record of the death is often necessary so that the children 
or other heirs may get the property. Or if the person who 
died had life insurance, the record of death may be neces¬ 
sary so that the person to whom the insurance money 
should go may get it. 

The records of deaths also show what things are causing 
the deaths of the people, how many are being killed by 
automobiles, and how many are being killed by typhoid 
fever, tuberculosis, measles, and other diseases. These 
are things we must know if we want to protect our lives 
against the things which destroy us. 

Questions 

1. Why is it important that the birth of every baby be officially 
recorded? 

2. Tell some of the advantages of having one’s birth recorded. 

3. Why is it important that deaths be officially recorded? 


APPENDIX 

By Belva E. Cuzzort 

Directions for Keeping Clean 

The Bath 

Take a bath in cold, warm or hot water as it suits you best. 

Take care to find which does suit you best. 

You should feel warm and good after a bath whether it has been 
a cold, warm or hot one. A good rubbing with a towel brings glow 
and warmth if your bath has been the right kind for you. 

It is good for the skin to be quite warm, like a hot towel at times, 
and cold at times. The changes train it and make it better able 
to do its work. Air and sunshine do it good also. 

The bath, except when taken to clean the body, should not take 
more than two or three minutes. I it is dragged out for several 
minutes, especially in a room that is too cold, the body will be 
chilled and that is bad. 

A bath of warm water and soap to clean the body should be 
taken twice a week or oftener. Clean underclothing is needed at 
least once a week. 

To Keep Scalp and Hair Healthy 

Keep the whole body healthy. Do not stay fatigued. 

Exercise the scalp every day by brushing the hair well with a 
brush of good bristles. Take 60 to 75 strokes. 

Use your own comb and brush. Keep comb and brush clean. 
Aim to have glossy clean hair. 


215 


216 PHYSIOLOGY, HYGIENE, AND SANITATION 


To Care for the Nails 

Wash in lathery warm suds. Use a brush to clean the edges. 
Do not run metal points under the edges. This makes them 
rough and dirt collects. Use a soft orange wood stick or other 
soft stick with or without cotton. 

Do not ever bite the nails. File them. Use nail scissors to cut 
hang nails away. Give the nails good care and they will show it 
no matter what your work is. 

Do not handle food with unclean finger nails. 

How to Care for the Hands and Face 

Too frequent washing the face in very warm water is not best 
for it. The hands should be washed in warm water and soap 
oftener than the face because they collect more dirt. The face 
and neck and ears should be washed with a soft cloth, using warm 
water and soap once a day. It may be rinsed in cold water often. 

It is such care as this and good health that give the skin a 
clear smooth appearance, and a good glow. 

Pasteurizing Milk at Home 
Three Ways 

First. Bring the water in the larger vessel to a boiling point, 
take the vessel off the fire and put in it a smaller vessel that con¬ 
tains the milk. Let it stand on table or cool part of stove, 20 or 
25 minutes. Be sure that the cover fits tight. At the end of the 
time put the milk in cool vessel, well covered, and cool at once. 

Second. Another way is to put the vessel holding the milk in 
the larger vessel containing the water before the water is heated. 
Heat, bringing milk to 145 0 (Fahrenheit). Then take it off the 
fire, wrap a heavy toweling kept for the purpose around the entire 
boiler and so keep the heat in for 20 to 25 minutes. Again put 
away to cool. 

Third. By this plan, the milk is put into bottles first. The 
bottle mouths are covered with the paper covers made for the 


APPENDIX 


217 


purpose. Set them in a pail that has in it a false bottom into 
which the bottles fit. Punch a hole into the cover of one bottle for 
the thermometer. Fill the pail with water nearly to the level of 
the milk, and heat until the milk shows 145 to 150 degrees F. 
Then take the bottles from the pail, put a new cover on the bottle 
that held the thermometer, cover with a towel, and allow to stand 
20 to 25 minutes. Then put in a cool place. 

By the third-plan, the milk is kept covered until time to use it. 
For sick people and for small children who should have milk as 
free from bacteria as possible, this is important. 

Pasteurizing Milk for the Baby 

Any of the three ways may be used but the third plan of heating 
in the baby’s bottle, keeps the milk from the air and from being 
poured from vessel to vessel. Keep two bottles ready, so if one 
breaks, there is another at hand. 

Caution in Pasteurizing: 

1. Do not overheat. This cooks the milk. 

2. Do not pour the Pasteurized milk in vessels that have not 
been scalded just before using. This admits germs and it is to 
destroy germs and bacteria that the milk is Pasteurized. 

The Iceless Refrigerator 

Construction. — A wooden frame is made with dimensions 42 by 16 by 14 
inches and covered with screen wire, preferably the rustless type, which costs 
little more than the ordinary kind. The door is made to fit closely and is 
mounted on brass hinges, and can be fastened with a wooden latch. The bot¬ 
tom is fitted solid, but the top should be covered with screen wire. Adjustable 
shelves can be made of solid wood or strips, or sheets of galvanized metal. 
Shelves made of poultry netting on light wooden frames, as shown in the illus¬ 
tration, are probably the most desirable. These shelves rest on side braces 
placed at desired intervals. A bread baking pan, 14 by 16 inches, is placed on 
the top and the frame rests in a 17 by 18 inch pan. 

All the woodwork, the shelves, and the pans should receive two coats of 
white paint and one or two coats of white enamel. This makes a very attractive 
surface and one that can be easily kept clean. The screen wire also may 
receive coats of enamel, which will prevent it from rusting. 


2 l8 physiology, hygiene, and sanitation 


A cover of canton flannel, burlap, or duck is made to fit the frame. Put the 
smooth side out if canton flannel is used. It will require about three yards of 
material. This cover is buttoned around the top of the frame and down the 




Framework of Iceless Completed Iceless 

Refrigerator Refrigerator 

Courtesy U. S. Department of Agriculture 

side on which the door is not hinged, using buggy hooks and eyes or large 
headed tacks and eyelets worked in the material. On the front side arrange 
the hooks on the top of the door instead of on the frame and also fasten the 
cover down the latch side of the door, allowing a wide hem of the material to over¬ 
lap the place where the door closes. The door can then be opened without 
unbuttoning the cover. The button of the cover should extend down into the 
lower pan. Four double strips, which taper to 8 or io inches in width, are 
sewed to the upper part of the cover. These strips form wicks that dip over 
into the upper pan. 

The dimensions given make a refrigerator of very convenient size for house¬ 
hold use, but it may be made higher and bigger. 

Care. — The refrigerator should be regularly cleaned and sunned. If the 
framework, shelves, and pans are white enameled they can more easily be kept 
in a sanitary condition. It is well to have two covers, so that a fresh one can 
be used each week and the soiled one washed and sunned. 







APPENDIX 


219 


Digestion of Foods 

Digestion begins with the work of glands. Glands are in the 
lining of the mouth, stomach and small intestine. Besides, there 
are the two large glands, pancreas and liver, that send their juices 
into the small intestine. 

In the mouth are the salivary glands, secreting the saliva. This 
does more than moisten the food. It starts the digestion of the 
starches, and changes some sugars into the kind the body can use. 
It is a serious matter for some foods to be swallowed without being 
mixed with saliva or for the starch in foods to be left half raw so that 
saliva does not act on it well. 

The gastric juice which the gastric glands of the stomach walls 
secrete has pepsin and acid in it. The lean of meat, and proteid 
of other foods are digested by it. Besides the acid destroys bac¬ 
teria that would otherwise be harmful to good digestion. This 
juice is not secreted evenly all day long, but there is more of it 
when we eat. The food in the stomach is mixed with the gastric 
juice by the action of muscles in the stomach walls. 

The stomach has its peculiar way of holding the food for a time, 
and then of letting it pass into the small intestine at just the right 
time. If the food has not been well chewed and there are big 
pieces the stomach’s work is made harder. 

Each digestive organ has its own work. In the small intestine 
there are intestinal juices, besides the pancreatic juice and the bile 
from the liver. Here digestion is completed. The walls of the 
intestine are of a velvet-like texture. They absorb the food. 

Digestion of a hearty meal cannot go on when the blood is in the 
muscles or brain. There is not enough blood in the body to pro¬ 
vide for all kinds of work at once. If there were, it would take a 
bigger heart to pump it and larger lungs to furnish it with oxygen. 

Taking time to eat a meal, resting after strenuous exercise, be¬ 
fore beginning to eat, and giving the digestive organs time for their 
work after the meal, are necessary. The muscle walls and the 
glands used in digestion need food that only the blood can bring. 


220 PHYSIOLOGY, HYGIENE, AND SANITATION 


First Aid Information and Practice 

Bandages 1 

Make of gauze, unbleached muslin, or cheese cloth. If an 
emergency arises and no bandages are made use fresh laundered 
pillow slips or handkerchiefs. A perfectly safe bandage is one that 
has been made clean, and put into a paper slip so that dust and 
fingers do not reach it. 

The triangular bandage is made from a square having a side 
not less than 34 to 38 inches in length. The square is cut 
diagonally across. 



Courtesy Bureau of Mines 
(1) The Narrow Folding Started 



Courtesy Bureau of Mines 
(2) The Same with Folding Completed 

Note how neatly and evenly it is done. 


1 See First Aid Book of American Red Cross for further information about 
bandages. 













APPENDIX 


221 



(i) Use of Triangular Bandage 



(2) Use of Triangular Bandage 



Courtesy Bureau of Mines 


(1) A Roller Bandage of Cheese Cloth 

Notice that only the edges are touched in holding it. 










PHYSIOLOGY, HYGIENE, AND SANITATION 



(2) The Beginning in Using a Narrow Roller 
Bandage on Finger 

Notice again that only the edges of the bandage are touched. 

(A little difficult.) 



Courtesy Bureau of Mines 

(3) A Finger Bandaged 

Another way of using roller bandage on the finger. 
(Requires care to do properly.) 







APPENDIX 


223 


The roller bandage is made of narrow strips of material, usually 
cheese cloth or gauze rolled so that it is kept smooth and straight. 
These rolls sealed in paper packages may usually be bought. It 
is narrow or wide, depending on whether it is used on the finger, 


arm, leg, chest, or abdomen. 
To make this bandage and keep 
it clean, one must follow direc¬ 
tions such as a doctor or nurse 
may give. Bandages not safe 
may, if put on a wound, cause 
blood poisoning. The illustra¬ 
tions on page 222 show the roller 
bandage and a few of its uses. 

From a piece of roller band¬ 
age two or three feet long a 
four-tailed bandage can be made 
by folding the bandage the long 
way and splitting this fold, 
leaving a space at center four or 
five inches long unsplit. 



Courtesy Bureau of Mines 

Use of the Four- 
Tailed Bandage 


Wounds 

Do not put your hands on a wound. If the wound is not deep 
so there is no danger of germs being left alive and washed farther 
in, warm water that has been boiled or a solution of half water and 
half peroxide of hydrogen may be used to wash the wound. Tinc¬ 
ture of iodine painted on a fresh wound is of the greatest help in 
destroying germs. It may be put on with a torn bit of a clean 
handkerchief soaked in it, for it destroys the germs on the hand¬ 
kerchief as well as in the wound. It should touch every part. 
The Red Cross First Aid Manual warns against using it near the eye 
and says it is better not to wash the wound before using the iodine. 
You see how valuable it is to know what to do and to have bandages 
ready in case of emergency. 



224 PHYSIOLOGY, HYGIENE, AND SANITATION 


Stopping Bleeding from an Artery 

Tie bandage between the hurt part and the heart. The blood 
from an artery is bright red. It comes out in spurts as the heart 
beats. The cutting of a big artery may cause a person to bleed to 
death. Stop the bleeding before treating the wound. Do both 
as soon as possible. 

In order to stop the bleeding in the safest and best way, learn 
to make a tourniquet. 



Courtesy Bureau of Mines 
Tourniquet Bandage for Bleeding 


Place a smooth round stone in a cloth. Lay this over the artery 
on the side of the wound next to the heart. Take a bandage and 
pass it over the stone and around the limb. Tie the bandage in a 
knot but far enough from the limb that a stick will pass through. 
Twist the stick until the bleeding stops. 

Stopping Bleeding from a Vein 

The blood from the vein is dark and flows evenly and does not 
spurt. Tie the limb on the side of the wound away from the heart. 





APPENDIX 225 

Do not tie so tight that the end of the limb will have no circulation 
of blood at all, just tight enough to stop bleeding. 

Bleeding of Small Blood Vessels — The Capillaries 

This blood flows slowly and the blood will soon clot enough to 
stop it. We would bleed to death if blood did not clot. 

Treat the wounds no matter whether artery, vein, or capillaries 
are injured as described on the preceding page. 




Bandage for Burn 
on Chest 


Courtesy Bureau of Mines 

Showing How Bandage 
is Fastened 


Burns 

Burns should, as soon as possible, be protected from air. Where 
the skin is broken, special care should be taken to keep germs 
away. A weak picric .acid solution is good to use on a burn. If 
this is not at hand, baking soda will do. A physician should be 
called if the burn is on a main part of the body, for it may be seri¬ 
ous even when it does not seem so. Proper bandaging is the best 
way to protect a burn from the air. See illustrations above. 







Courtesy Bureau of Mines 

Artificial Respiration — (2) Air Going out of the Lungs 


226 PHYSIOLOGY, HYGIENE, AND SANITATION 

Drowning 

After the person is rescued at once get water out of lungs and 
stomach. Lay him over a log or over another person who is on 
hands and knees or lift him by clasping your own hands under 


Courtesy Bureau of Mines 

Artificial Respiration — (1) Air Going into the Lungs 







APPENDIX 


227 


his stomach as you stand at his back. This lets the water run out 
of his lungs. Next put him in a position where you can give arti¬ 
ficial respiration. Notice in the photographs below the man is 
lying on his face, though his head is on his elbow and turned so he 
can get air. The other arm is thrown out. 

To perform artificial respiration do this: Place yourself as the 
man in the picture on page 226. Put your hands a few inches above 
the small of the back of the rescued person — the fingers pointing 
slightly up and toward the front. Press with all your force. Do 
not bend your elbows. Let the weight of your body from your 
knees up rest on your hands. This forces air out of the lungs. 
Then take your weight away — leaving your hands in position. 
The chest becomes larger and air goes to the lungs. Do not take 
your hands away as you do this. Get a rhythmic motion. You 
should press about every four seconds. It takes practice to learn 
to perform artificial respiration. 

A First-Aid Kit 

If your school has a first-aid cabinet that has been purchased 
with supplies find what supplies are there that you know how to 
use. 

If you collect your own supplies, you should have the following 
because your first-aid knowledge enables you to use these. 

Soap , towel , to use in washing your hands. Also solution of half 
peroxide of hydrogen and half water in case you can not have 
water that has been boiled to wash hands in. 

Roller bandages of different width — in sealed paper packages. 
Triangular bandages in wrapped packages. Absorbent cotton. 

LugoVs solution of iodine. 

Scissors , safety pins. 

Can of 11 canned heat ” and cup in which water can be heated. 
Box of safety matches. 

Tea , coffee for stimulants. Mustard to use in making a person 
vomit. 


228 PHYSIOLOGY, HYGIENE, AND SANITATION 


Aromatic spirits of ammonia for stimulant. 

Picric acid , and baking soda for burns. 

Stone and stick for tourniquet bandage. 

In addition to the kit you should know the telephone number 
of the fire department if your town has one. If it does not have you 
should know the quickest way to attach small hose to the house 
water supply. You should know the telephone number of the 
hospital if there is one near you and of your doctor and another 
doctor in case you cannot get your own at once. You should also 
observe who of your neighbors know how to treat accidents in 
emergency. Information, common sense and the first-aid kit 
should grow large together in first aid. 


INDEX 


Abdomen, muscles of, 20 
Air, breathed by lungs, 42; dust 
and pollen in, 65; why we breathe, 

65 

Alimentary tract, 34 
Anopheline mosquitoes, 130 
Arm, bones of, n 
Arteries, the, 32 
Artificial respiration, 226 

Backbone, the, 9 
Bandages, 220, 221, 223 
Bathing, 85, 215 
Bedrooms, 153 

Births, how and why recorded, 213-214 
Bleeding, stopping of, 224 
Blood, the, 32; oxygen of, 39; red 
and white corpuscles of, 39; what 
it does for our bodies, 39 
Blood vessels, 32; in the skin, 83 
Bodies, our, 3; how constructed, 5; 
injured by sickness and disease, 5; 
their care and training, 4-5, 68 
Body louse, spread of disease by, 127 
Bones, the, 7-13; blood vessels and 
nerves in, 9; contain lime, 7; their 
purpose and shapes, 7 
Bowel movements, 77 
Brain, the, 9, 25; made up of cells, 25; 

what it does for us, 29 
Burns, treatment of, 225 

Caffein, 59 

Calcium, 52; in milk, 52; need of in 
food, 52 

Carbohydrates, 50, 51 
Caring for the sick, 122 
Cellars, 145 

Central nervous system, 25 
Chest, the, 10 

City health departments, 190; aid 
persons having tuberculosis, 199; 
control of disease by, 192, 194; 


protect families of sick, 198; protect 
food supplies, 197, 202, 203 
Clothes, 99 
Coffee, 59 
Condiments, 59 
Consumption, 133 

Deaths, how, and why recorded, 214 

Dentin, 88 

Dermis, 80 

Diaphragm, the, n 

Digestion, 35 

Disease, no; causes of, 110-113; 
how spread, 117; how to keep from 
getting, 121; spread by body louse, 
127; — by drinking cups and glasses, 
117; — by fleas, 127; — by flies, 118, 
123; — by handkerchiefs, 117; — by 
milk, 124; — by mosquitoes, 119, 
127; — by polluted water, 123; — by 
sewage, 185 

Drink, purpose of, 63; what to drink, 62 
Drowning, 226 

Enamel of teeth, 88 
Epidermis, 80 
Esophagus, 34. 35 

Eyes, the, 94; far and near sighted, 97; 
reading and studying, 95; their 
care, 94 

Face, bones of, 9 
Fats, 50, 51 

Feet, the, n; crippled by shoes, 14, 
100 

Flat foot, 14 

First aid, 220; first aid kit, 227 
Fleas, spread of disease by, 127 
Flies, spread of disease by, 118 
Food, 34, 49; carbohydrates, 50, 51; 
chewing of, 35; coffee, 59; condi¬ 
ments, 59; fat, 50, 51; for boys 
and girls, 55; fried food, 59; fruits, 


229 


230 


INDEX 


56, 58; how it nourishes, 34; pastries, 
59; pickles, 59; proteids, 50; tea, 59; 
vegetables, 56, 58; vitamins, 50, 53; 
what to eat, 49 
Foot, 13; bones of, 13 
Forearm, n; bones of, xi 
Fried food, 59 
Fruits, 56, 58 

Garbage, care of, 158 
Gastric juice, 36 
Germs, 103 

Habits, 75 

Hair, 81, 82; care of, 215; washing 
of, 85 

Hand, the, 11; bones of, 11; washing 
of, 216 

Hay fever, 65 

Head, the, 9; bones of ; 9 

Health departments, 190; city, 190; 

state, 205; what they do, 190 
Health laws, 206 
Health officers, 191 
Heart, the, 32; muscles of, 21 
Heating of home, 147; hot air fur¬ 
naces, 147; hot water, 149; steam, 
148; stones, 147 
Hip bones, 12 

Home, the, 143; bedrooms, 153; cellars, 
145; floors, 158; heating, 147.: 

kitchen, 154; location of, 143 
Hot air furnaces, 147 
Hot water heat, 149 
Houses, 143; cellars of, 145; what 
built of, 144 
Hunger, 76 

Infant welfare stations, 201 
Inorganic salts, 50, 51; purpose of 
in food, 51 

Insects, spread of disease by, 127 
Intestines, 34; emptying of, 77 
Involuntary muscles, 21 

Jenner, Edward, 138 

Kitchen, 154 

Knee, 13; knee caps, 13 

Laws, health, 206 
Leg, the, bones of, 12 


Lime, 7, 52; in bones, 7; in milk, 52 
Louse, spread of disease by, 127 
Lungs, the, 42, 44; their purpose, 42 

Malaria, 119, 127 
Marrow of bones, 7 

Microbes, 103; bad microbes, 107; 
disease due to, 113; food microbes, 
10b; how they grow, 105; in bowel 
movements, 118; in milk, 167, 168; 
in the mouths of the sick, 118; 
of tuberculosis, 133; on drinking 
cups and glasses, 117; on handker¬ 
chiefs, 117; spread by flies, 118; 
— by mosquitoes, 119; what they 
are, 103; where they came from, 103 
Milk, 37, 50, 165; calcium in, 52; care 
of, 175; disease microbes in, 168; 
food microbes in, 167; handling in 
city, 173; pasteurizing at home, 216- 
217 

Milk bottles, care of, 175 
Milk teeth, 87 

Mosquitoes, 129; anopheline, 130; 

spread of disease by, 127 
Mouth, the, 34 

Muscles, the, 117; fatigue of, 22; 
give the body its shape, 20; grow 
stronger by use, 22; how they act, 
17; involuntary, 21; of heart, 21; 
produce heat, 21; striped, 21; their 
shape, 19; unstriped, 21; volun¬ 
tary, 21 

Nails, finger, care of, 216 
Neck, bones of, 10 
Nerve fibers, 25 

Nerves, the, 25; how they control 
the body, 25; what they do for us, 
27 

Nicotine, 60 

Oil glands, 81, 82 
Outdoor air best for body, 66 
Outdoor toilets, 188 

ut 

Oxygen, 42; how used by the body, 45; 
in blood, 39; source of, 42 

Pastries, 59 

Pelvis, the, 12; bones of, 12 
Perspiration, 41 
Phagocytes, 114 


INDEX 


231 


Phalanges, 11, 13; of foot, 13; of 
hand, 11 
Pickles, 59 
Plague, 127 
Play, 68 

Proteids, 50; purpose of, 50 
Privies, 188 

Public Health Service, of United 
States, 209 

Public water supplies, 182 
Pulp of teeth, 87 
Pupil of the eye, 94 

Rainwater, 180 
Red corpuscles of blood, 39 
Refrigerator, iceless, 217 
Regular daily habits, 75; bowel move¬ 
ments, 77; brushing the teeth, 78; 
eating, 76; getting up in the morn¬ 
ing, 76; going to bed, 75 
Regulations, health, 206 
Ribs, the, 10 
Roots of teeth, 88 

Saliva, 35 
Scalp, care of, 215 
Sebaceous glands, 81, 82 
Sewage, 185; disease spread by, 185; 
how disposed of, 185; how purified, 
187; in small towns, 187; why dan¬ 
gerous, 185 
Sewers, 186 
Shin bone, 13 
Shoes, 100 

Shoulder, bones of 12 
Sick, how to care for, 122 
Skeleton, the, 7; what it does for us, 7 
Skin, the, 80; care of, 80, 84; dermis, 
80; epidermis, 80; hair of, 81, 82; 
purpose of, 80, 82; sebaceous glands, 
81, 82; sweat glands, 81 
Skull, the, 9; how constructed, 9 
Sleep, 29, 30; how much is needed, 73; 
its purpose, 71, 72; why the body 
needs it, 71, 72 

Smallpox, 138; vaccination in, 139 
Spinal column, 9; how constructed, 9 
Spinal cord, the, 10, 25; made up of 
cells, 25 
Stables, 160 

State health departments, 205 
State health laws, 206 


Steam heat, 148 
Sternum, the, 10 
Stomach, 34, 36 
Stoves, 147 
Striped muscle, 21 
Sweat, 81; sweat glands, 81 

Tea, 59 

Teeth, the, 87; brushing of, 78, 90; 
care of, 87; dentin of, 88; enamel 
of, 88; milk teeth, 87; need exer¬ 
cise, 89; need proper food, 89; 
repair of, 91; roots of, 88; second 
teeth, 87; structure of, 87 
Tendons, 20 

Thorax, the, 10; bones of, 10 
Throat, 34 
Thumb, bones of, 11 
Tibia, 13 

Tobacco, 60; effect of use of, 60 
Toes, bones of, 13 
Toilets, outdoor, 188 
Toothbrush, use of, 90 
Trachea, 44 
Tuberculin test, 169 
Tuberculosis, 133; how to keep from 
getting, 135; how to protect others, 
134 

Typhus fever, 127 
Ulna, 11 

United States Public Health Service, 
209; examines immigrants, 212; 
maintains maritime quarantine, 211; 
studies causes of disease, 210; work 
of, 209 

Unstriped muscle, 21 

Vaccination, 138, 139 
Vegetables, 56, 58 
Veins, the, 32 
Vertebrae, the, 9 

Vitamins, 50, 53; necessary in food, 53 
Voluntary muscles, 21 

Water, 37, 40, 62, 178; drilled wells, 

181; driven wells, 182; in the body, 
62; its importance, 178; necessary 
to the body, 37, 62; public water 
supplies, 182; surface wells, 180; 
when unsafe to drink, 179 
Wells, 180-182 


INDEX 


232 


White corpuscles of blood, 39 
Wigglers, 129 
Wiggle-tails, 129 
Windpipe, 44 
Work, trains body, 68 


Wounds, treatment of, 223 
Wrist, bones of, 11 

Yards, care of, 160 
Yellow fever, rig, 127 





